My phone beeped, indicating I had just received a text message. I put down the book I had been reading and snatched up the device. My lips curled into a smile when I recognized the name on the screen. Candi Sweet, AKA my sister. I read the short message.

Sunbathing by the pool. Want to join?

My smile widened even further. Though it was my birthday—my eighteenth birthday—I had nothing planned. Well, nothing but a relaxing day spent lying around the house. Joining Candi by the pool sounded like a nice change of pace. Plus, my sister and I had not hung out in nearly a month. I had a serious craving that could only be filled with Candi.

As promised I found my sister by the pool. Her barely concealed frame was stretched out across one of the half dozen lounge chairs that lined the edge of the pool. The bikini she had selected for the occasion was ideal for sunbathing. The only downside was that the lack of fabric left almost every inch of her frame exposed. Only the very most private parts of her anatomy remained covered.

“Hey, sis.” Candi’s voice made me jump. I tore my gaze from her body and focused on her face. Her eyes were open and focused on me.

“Hi,” I said as I settled into the chair to my sister’s right. Unlike her, I wore a rather conservative bathing ensemble. Though it was a bikini, it kept my breasts, slit, and butt completely covered. Well, almost completely.

There was a moment of silence before Candi spoke again.

“How does it feel to be an adult?”

“Pretty much the same,” I said. To be perfectly honest, I hadn’t really thought about it. To me this was merely another birthday. Nothing special about it. Or so I thought.

“Not for long,” muttered Candi. She spoke so softly that I almost didn’t hear her.

“What does that mean?” I asked.

“You’ll find out soon enough.”

I insisted a little more, but it soon became clear Candi would not tell me whatever it was she was hiding from me. I had no choice but to try and forget about it.

We spent the next few hours exchanging small talk. Every so often the sun’s warm rays would get too much for me to handle and I would go for a dip in the pool. I could have invited Candi to join me, but I knew it was useless. My sister hated water, be it from showering or rainstorms. She had not taken a bath in years. The last time I had seen her in the pool was when we were kids, and that was merely because she has slipped and fallen in. The only type of water she could handle was the kind you drink. She suffered through showers, but only because she didn’t want to smell. It would have made sense if she was a cat, but for a human, it was quite peculiar. But I was accustomed to her odd phobia.

I had just emerged from the pool for the third time when my sister asked the most unexpected question of the entire day. So far.

“Do you mind if I remove my bikini?” she asked.

My heart skipped a beat. I knew Candi had no problem letting others see her naked, but I was far more conservative. The last time another person had seen me naked was two years ago, when I had lost my virginity to Scott. But that’s another story.

“All of it?” I asked, terrified that she would answer with a nod.

“That depends on you,” she said.

“Wh-What does that mean?” I asked, suddenly nervous.

“It means that if you agree to take your top off, I will do the same,” she explained. “But if you refuse, then I will remove my bottom as well.”

My heart skipped another beat. Candi had not seen my topless in years. In fact, she had not once seen my breasts since they had emerged from my chest nearly five years earlier. But was keeping them hidden worth running the risk of seeing my sister naked?

“Why are you doing this?” I asked.

“What?” said Candi innocently. “I’m just trying to be fair. I want to sunbathe naked, but you don’t want me to. If we’re both half naked, it evens out.”

It was logical, yet no less scary for me. I could simply have retreated to the safety of the house and left Candi to her naked sunbathing, but I refused to let my shyness dictate my behavior. If that meant that I had to go topless, then so be it.

“All right,” I said, unfastening my bikini top before I could change my mind. Candi seemed surprised by my audacity, but the stunned expression soon fell from her lips. Moments later we were both topless. I couldn’t help feeling relieved when I noticed my breasts were slightly bigger than hers. But that doesn’t mean I felt comfortable letting her see me half naked. Unfortunately it was too late for that.

Candi took a few seconds to study my breasts, then returned to sunbathing. Neither of us spoke for a few minutes. I was beginning to relax when she spoke.

“There’s something I’ve been waiting to tell you,” she said. “I would have told you before, but Mom and Dad refused as long as you were underage.”

“Why?” I asked, suddenly intrigued.

Candi sat up and turned to face me. My gaze momentarily landed on her breasts, but quickly moved on to her face. She looked nervous, which wasn’t like her. Whatever it was she was about to tell me, it was serious.

“What is it?” I asked when she did not speak for a few seconds.

“I need to show you something,” she said as she stood up. “It’s kind of weird, but please don’t freak out.”

My heart was racing, but I nodded to indicate I understood and was determined to try and keep from overreacting. I watched, worry coursing through me as Candi reached down and removed her bikini bottom. For a brief moment I half expected to see a cock, but one glance at her slit—it was clean shaven and looked incredibly tight—told me that was not the secret she was keeping. But if not that, then what?

“Ready?” she asked.

“Not really,” I admitted.

Candi chuckled. But the laughter faded as she began to transform. Her body collapsed upon itself, shrinking at a drastic rate. Black fur spouted across her entire body. A tail emerged from her lower back. Claws replaced her nails. Her ears grew pointy and shifted to the top of her head. Her nose shrunk until only a small triangle remained. Whiskers emerged from her cheeks. But it was not until her pupils narrowed that I realized what she had transformed into.

A cat.

I opened my mouth to speak, but no words came out. Only a high-pitched whimper emerged. The cat that my sister bad become strolled back and forth a few times, then began changing again. Within seconds, Candi was back to her old self. Her lack of clothes no longer bothered me. I had far more freaky things to worry about.

Neither of us spoke for the longest time.

“Well,” finally said Candi. “What do you think?”

I took a few second to consider my answer.

“It was… awesome!” I finally said. There was no denying that my sister’s strange ability was frightening, but it was also incredibly cool. Not to mention the fact that it explained my sister’s aversion to water. Cats hate water and so did Candi.

“Really?” asked my sister. I could tell she was relieved. Though she acted like nothing bothered her, I sensed that revealing her secret had been very scary for her. Perhaps even scarier than it was for me to find out that my sister was a cat. Speaking of which…

“How is that possible?” I asked.

Candi’s lips curled into a smile.

“I’m not really sure,” she admitted. “I only know that it’s unique to our family.”

It took me a moment to figure out what that meant.

“Are you saying that Mom and Dad…” I began.

“That’s right,” said Candi. “Our parents are shapeshifters too. So is Kyle.”

I couldn’t believe it. My parents, my sister and my brother were shapeshifters. Why was I the only one who couldn’t shift? Unless…

“Why didn’t Mom and Dad want you to tell me until I was an adult to tell me?” I asked.

Candi’s lips curled into a knowing smile. She had clearly understood the conclusion I had arrived to.

“That’s right,” she said. “You can only shift when you’re an adult.”

I was so excited that I had a hard time speaking.

“Does that… Are you… How do I…”

Candi chuckled.

“Don’t worry,” she said. “I’ll explain everything.”

I waited for her to continue.

“The first thing you must understand is that everyone is different. I’m a cat, but you could be dog, a parrot or even a mouse.”

“That’s all right,” I assured her. Most of me meant it, but some small part could not help being worried. What if I turned into something gross? Like a cockroach? Or a spider? Yuk! I hate spiders. But even if the animal hidden within my genes was not as cool as a cat, it would still be incredible.

“There are two things you must do before you can shift,” explained Candi. “The first one is wait until you’re eighteen. The second is…” she paused, as if afraid of how I would react to whatever it was she was about to tell me. “…you must have sex with a family member.”

I didn’t react for a few seconds.

“What the fuck?” I finally said. “Are you serious?”

My sister nodded. “The shifting gene is already within you, but the only way to activate it is through incest. If you want to shift, we need to have sex.”

I took a moment to let the new information sink in.

“Are you saying that you…” I began, but I couldn’t bring myself to finish the thought.

Candi nodded.

“I had sex with Mom and Dad.”

I couldn’t believe it.

Incest was bad enough, but finding out she had sex with both our parents somehow made it worse. Not that I could blame her. If incest truly was the only way to activate the shifting gene, I probably would have done the same. In fact, I was about to. The only difference was that my lover would not be my parents, but my sister. I wasn’t sure if that was better or worse.

“Do you swear this isn’t some kind of joke?” I asked.

“Cross my heart and hope to die,” she replied. It was the promise we used as children to prove we were being honest.

“Okay,” I finally said. “Let’s do it.”

Candi’s lips curled into a smile.

“Are you sure?”

“No,” I admitted, “but let’s do it anyway.”

My sister chuckled. “All right,” she said. Moments later she was back in her cat form.

She hopped up onto my lounge chair and came to stand between my legs. She pawed at my bikini bottom, indicating she wanted me to remove it. I hesitated, but the thought of being able to shift convinced me to overcome my shyness.

I stood up and slowly slipped out of my final piece of clothing. Candi started purring loudly. It was probably her way of saying I looked hot. Either that or she was looking forward to tasting me.

“Fuck!” I yelled as my sister’s small, spike-covered tongue slid across my labia. I was back on the lounge chair, legs spread wide and chest rising and falling to the rhythm of my rapid breaths. I had never been this scared. Yet as the same time I was incredibly excited. And not just because of the shapeshifting. This was my first lesbian experience. It was also my first bestial experience. And my first incestuous experience. But above all else, it was my first sexual experience as an adult. I guess Candi had been right when she claimed my life would be different now that I was an adult.

My sister’s barb-covered tongue raked at my labia, causing pain to erupt across it. I probably should have been worried, but I didn’t care. I would have endured far worse in the name of unlocking my shapeshifting gene. I didn’t even cry out when the spiked tongue slithered across my clit. Pain shot through me, but also arousal. As impossible as it seemed, I enjoyed the feel of my sister’s tongue on my clit. In fact I enjoyed it so much that I began moaning softly. Moments later Candi started purring. She increased the intensity of her tongue strokes. Within seconds it was darting back and forth across my clit. The pain was still there, but it had mixed with the arousal that now filled me, creating an oddly pleasurable pain-pleasure cocktail. Actually it was so enjoyable that I soon lost all control.

“Fuck me!” I begged. It wasn’t until my sister’s tongue slid into my slit that I realized the words had come from me. But the wetness of my slit, partnered with the power of my moans, told me I didn’t regret the escalation. In fact I literally started wailing when Candi’s tongue began darting in and out of me.

I was stunned by how deep it travelled. Though narrow, the tongue was unexpectedly long. It glided deep into me, hovered there a second, then slid back out. The barbs, which should have ruined an otherwise enjoyable experience, only made my first time with an animal more enjoyable. As did the knowledge that said animal was my sister. I moaned and begged for more. And that was exactly what I got. Before long Candi’s tongue moved so quickly that I could no longer tell when it was in and when it was out. All I felt was an overwhelming sense of excitement. I could feel the orgasm growing within me. And with it the promise of shapeshifting.

“I’m gonna come!” I warned, though I’m not sure who I was warning—my sister or myself?

The orgasm ripped through me moments later. It shook my entire body, forcing squirt after squirt to gush out of my slit. The hot nectar splashed into my sister’s face, but she didn’t seem to mind. She kept purring as her tongue darted in and out of me. I did the same, though I used moans to voice my ecstasy. But it mattered little, because the entire world seemed to have faded away, leaving only my orgasm behind. I continued focusing on it until the final squirt oozed out of me and my trembling body grew still. With one final moan, my first orgasm as an adult officially came to an end.

I lay there for a while, panting heavily. Candi took advantage of this to lick the cum that clung to her fur. By the time my strength returned and I sat up, most of it was gone. Only the drops that clung to her face remained.

Deep down I knew I should be ashamed of my perverse behavior, but all I felt was an overwhelming sense of excitement. Now that Candi had brought me to climax, it was time for me to learn to shift. But first I had to make sure my first incestuous encounter truly had come to an end.

“It is over?” I asked. “Can I shift now?”

Candi shook her head.

“What?” I half yelled, panic gaining me. “You promised!”

By the time the last word left my lips, my sister was back to her original self. I didn’t even notice her lack of clothes.

“I did,” agreed Candi, “but it takes more than just one orgasm to activate the gene.”

My heart skipped a beat. I didn’t know what my sister was about to suggest, but I could tell it would be perverse. Sure enough…

“I just licked your pussy to help you relax, sort of like a warmup,” explained Candi. “Plus, I’m a cat. I like pussy.”

The joke was so unexpected that I couldn’t help laughing. It helped me relax, and I was able to think clearly for what felt like the first time in ages. Though incest—and bestiality—was both illegal and wrong, I was determined to activating my shifting gene. I had come too far to turn back now.

“All right,” I said before I could change my mind. “Let’s do this.”

My sister smiled, but her amusement was only temporary.

“There is something I need to show you first,” she explained. “Please don’t freak out.”

That couldn’t be good. What could possibly be worse than finding out my sister—not to mention my mother, my father and my brother—could turn into an animal at will?

Candi began to transform. I expected something freaky to happen, but she looked just as she had before. Short black fur. A tail. Pointy ears. Whiskers. And a surprisingly massive cock…

“Oh my god!” I gasped as my gaze landed on Candi’s member. It was only a few inches in length and even less in width, yet it seemed quite large for a cat. Not that I had ever seen a feline penis before. I guess that’s why I took a moment so study it. It was pink and covered in spikes. Not to mention fully engorged. I actually found myself drawn to it. But the fact that my sister had a cock was too freaky for me to accept without protest.

“You have a cock,” I said once Candi was back to her human self.

She nodded. She didn’t seemed ashamed, but she wasn’t exactly proud of it either.

“Why?” I asked when no explanation was provided.

“Honestly? I don’t know. That’s just how it works. Male. Female. It doesn’t matter. You will be a male animal when you shift.”

“That’s weird,” I admitted.

“Tell me about it,” said Candi. “Mom and Dad forgot to tell me the first time I shifted. Imagine my surprise when I found out I was a male cat.”

I couldn’t help chuckling. But that didn’t mean I wasn’t freaked out about the prospect of changing sex. At least I would know what to expect. Speaking of which, I had no idea what would happen next.

“What now?”

Candi’s lips curled into a broad grin. “Now I show you how great it can be to have a dick.”

Part of me was nervous, but the rest was surprisingly excited. It’s not every day you get to have sex with your sister. The fact that she was a cat and a male only made it more incredible, and thus more special. I actually felt myself grow wet at the thought of Candi’s cock sliding into me.

“Are you ready?” she asked.

I nodded. Moments later Candi was a cat once more. I watched with giddy excitement as she joined my on the lounge chair. Like before she came to stand between my legs. Only this time she didn’t press her tongue to my slit. Instead, she placed her front paws on my stomach and pressed the tip of her member to the mouth of my pussy.

Nothing happened for a few seconds, then she started purring. Moments later she jerked forward.

“Fuck!” I yelped as every last inch of my sister’s cock flew into me. It was far smaller than Scott—the man who took my virginity—’s, but the fear and excitement that coursed through me kept my pussy tight.

Candi kept her shaft within me for a few seconds, giving me time to get used to it. It was a nice gesture, but completely unnecessary. I had already grown accustomed to the feel of barbs raking at my vaginal walls, so the spikes that ringed her shaft weren’t an issue. The same could not be said about my sister’s apparent unwillingness to give in to her animalistic sexual hunger. Luckily, the arousal that now coursed through my veins had helped me overcome my shyness.

“Fuck me!” I ordered.

Candi was so surprised by my forceful outburst that she stopped purring. But once the initial shock faded the purring resumed. Moments later she began thrusting. The spiked cock glided in and out of me. Slowly at first, but with increasing speed. Before long it was moving so quickly that I lost track of it. But that may simply have been because I was moaning at the top of lungs. Or because the intensity of the incestuous pounding was making my heart race and my back arch. Or simply because a second orgasm was beginning to form within me. It was only a matter of time before it overpowered me completely. And then all hell would break loose.

The pounding continued for… well, I was so overwhelmed by the intensity of my sister’s powerful thrusts that I lost all track of time. The bestial encounter could have lasted mere seconds, like it could have lasted endless hours. I know only that my orgasm eventually became impossible to contain. One second I was moaning and begging for more. The next my entire body convulsed as I experienced the most intense climax of my entire life.

“FUUUCK!” I shrieked as squirt after squirt gushed out of me. Within seconds my thighs were slick with cum. But I wasn’t the only one affected by the onslaught of hot nectar. It clung to my sister’s legs and stomach, drenching her in seconds.

Candi reached the point of no return moments after the cum began spurting from my slit. Her shaft convulsed within me for a few seconds, then squirt after squirt gushed out of it. The semen mixed with my own cum and flew out of my pussy. The feel of it raining down upon me made me moan harder. Even my orgasm intensified. And it continued to rage until the last few drops of strength has been expended. I barely even felt the final squirt ooze out of me. One seconds I was moaning and writhing. The next I was sprawled across the lounge chair, panting heavily.

It took a while, but my strength eventually returned. And with it the excitement at the promise of being able to shift. I opened my eyes to find Candi licking the cum from my slit. She purred as she worked, refusing to give up until every last drop of cum had been lapped up. Only then did she pull away. Shifting back to her human form, she slid along my frame until she was lying atop me. She peered down at me, smiled and pressed her lips to mine. Moments later her tongue slipped into my mouth. But that’s not all that made its way past my lips. A surprising amount of arousal poured into my mouth. I probably would have been shocked had I not been distracted by my sister’s tongue, which darted in and out of my mouth. In fact I was so unprepared for the cum-filled kiss that I didn’t even hesitate before reciprocating her eager tongue strokes.

We kissed until the last few drops of cum slid down my throat. Only then did I realize just how perverse the make out session truly was. For some reason kissing my sister in human form seemed more perverse than letting her pound me to climax in cat form. Still, there was no denying how great a kisser she was.

There was an awkward moment of silence once our lips parted. Candi didn’t seem to realize just how immoral her actions were. Then again, she had sex with our parents. At least I didn’t have to do that. Not that having sex with my sister was any less perverse.

“Is it over?” I finally asked. “Can I shift now?”

Candy chuckled, then shook her head. At first I thought she was kidding, but then her smile faded and I knew she was being serious.

“But you… You promised!” I blurted out.

“And I kept my promise,” she replied. “I said the only way to activate the shifting gene is through incest, and that’s the truth.”

“Then why can’t I shift?” I asked, completely lost.

“Because this, as fun as it was, was merely the first step. The first of many.”

“What does that mean?”

All I got in response was a smile and a wink, followed by another passionate incestuous kiss. I guess I would just have to wait and see.

To be continued…

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