“Hey guess what!” she said excitedly. “My sister is going to be coming here for college!”

Oh great I thought, can’t wait to have to deal with your little sister coming over all the time. She was 18 years old and from what I could remember, had a shitty entitled attitude. She was the youngest of the 3 daughters and was by far the most spoiled.

“Oh.. that’s great!” I responded, doing my best to hide my annoyance.

I had gone to college in their hometown that was 4 hours away from where I lived, and had met Kate there. We began dating my junior year in college and had gotten married a year after we graduated. After graduation we moved back to my hometown. Her sister Ali was a Junior in High School when we graduated and I was sure she would be staying in their hometown for college. She was very attached to her mom and besides Kate, had no family on the other side of the mountain where we lived.

Ali was a volleyball player and was built like one. She had long legs and a great butt. Kate had a great butt too but Ali’s was bigger. Kate is 5”2 with large double D boobs and a perky butt with brown hair. Ali was 5”9 with small tits, maybe Bs, but a donk in the back and blonde. Besides them having the same nose, you wouldn’t know that they were sisters.

Fast forward a few months and Ali was now in college, living in the dorms just 10 minutes away from our house. At first we didn’t see her much. She was completely free in a new city and was enjoying her new privileges. We had lunch a few times over the weekends and she was much more mature now. Not nearly as annoying as I remembered her when she was in high school. Still, I thought of her as nothing but my wifes little sister. I had obviously noticed her big butt before but honestly hadn’t thought much of it.

“Hey Mike, what do you think about grilling some steaks tonight. We can have Ali over and maybe watch a movie later? She said she was getting a little homesick to me and I invited her to spend the night”.

I didn’t think much of it.

“Sure, that sounds fine.” I responded.

I headed to the store to buy some drinks and a few other things I needed. I came home and Ali was already over. She was wearing small daisy duke shorts and a spaghetti strap tank top. I couldn’t help but notice that her boobs looked bigger than I remembered them. They were at least C cups now, maybe even D. Could have been a push up bra I thought, either way, she was catching my eye.

“Hey Mike! Thanks for having me over!” She exclaimed as she headed towards me and gave me a hug.

I caught a scent of her perfume. It was amazing. A scent that to this day drives me wild.

“No problem Ali, we are happy to have you over!”

I realized that I was more giddy over the situation than I could have ever imagined. We had our BBQ and had some beers and Mike’s hard lemonades for the girls. She was 19 now, and was obviously drinking as a freshman in college so I didn’t care and neither did Kate. After sitting around on the deck for a while Kate suggested we get ready to watch a movie. We headed inside and I went upstairs to change into some sweats. I put them on and an athletic t-shirt and headed downstairs and sat on the couch waiting for the girls to come down.

Ali came down first and my jaw dropped. She was wearing these tiny shorts that covered half her ass and a sports bra only. I couldn’t believe she was wearing so little in front of me. She took a seat on the floor in front of me with her legs spread and started chatting with me. Small talk. Asking me about work and such. Her shorts were so little that with the way she was sitting exposed her panties through her leg opening. It was a cute white thong. I felt my cock start to swell as I couldn’t stop glancing as she talked to me. Doing my best not to get caught.

Finally, Kate came down.

“You guys ready?” She asked.

She had a blanket in her hand and was also wearing some small shorts but with a long ugly t-shirt that wasn’t nearly as sexy as Ali’s pink sports bra. I wondered what she thought of Ali’s attire but she never mentioned anything to me about it.

I had a large L couch with really only one spot to lay down on and we did our best to cram in. To my surprise, I got the middle. We picked out Insidious, a scary movie. Ali loved scary movies and Kate hated them but she agreed to watch it as long as she could close her eyes in the scary parts. We huddled in together and as the movie got scarier we shifted more from a sitting up pose to lying down. I had Ali nestled in on one arm and Kate on the other. I did my best to keep my head out of the gutter but couldn’t seem to be able to get the image of Ali’s cute white panties out of it. That and her scent near my face was making it nearly impossible to not get hard again.

Still I was more shocked at the overall situation I was in. Ali and I had never been close so the fact that she was comfortable enough to be laying on me wearing what she was wearing was pretty mesmerizing. And even more so that Kate didn’t seem to mind at all.

As we watched the rest of the movie, I painfully did my best to keep myself in check and not get fully hard but Ali’s hand on my chest and legs rubbing against mine did me in. I was fully hard under the blanket. Thankfully the lights were off so it wasn’t blatantly obvious but I worried that with the right light from the TV you might notice the tent I was pitching. I was even more worried about Kate seeing it. I don’t know how I would get out of that one, especially since we were watching a scary movie. A hard on was the last thing I should have.

Thankfully Kate spent most of the movie with her eyes closed that she was completely oblivious. I wondered if Ali could see it though. I wondered what she would think, or do.. I imagined her reaching under the covers and grabbing it.

“Stop dumbass” I thought to myself. “Stop letting your mind wander” It only made me harder.

The movie was almost over and I was still hard as a rock. I needed to think of something else before it ended or else I was fucked. The more I tried to think of something else the more I found myself thinking of her panties again and the thought of her sneaking a feel under the blanket. I needed a plan B.

“Sorry ladies but I really need to pee,” I said. They were both laying on me so they’d have to move so I could go. I figured this was my best shot, since it was still dark. The bathroom was to the right, which was where Ali was, so I needed to turn towards her to go to the bathroom. I stood up and did my best to conceal it with my hands as I headed to the bathroom. I didn’t look at her face as I got up so I couldn’t be sure if she saw anything but I secretly hoped she had.

I started to pee and thankfully this helped bring it down some but I had a bigger problem. My briefs were soaked in precum. I didn’t even realize how much I was leaking until then. “Fuck” I thought. I did my best to clean them off and made a mental note to hide them deep in the laundry basket so Kate wouldn’t see anything.

I came out and headed back to the couch and by this point Ali and Kate were cuddled in together laying sideways with Ali’s butt pointing towards me. I didn’t say anything and simply sat down next to Ali. Not wanting to have them get up again for me to get in and certainly not about to cuddle up behind her. I grabbed some blanket and purposefully lifted it a little higher than needed to get a quick peek at her butt perched out. Still, sitting upright while they spooned. My thoughts started to get the best of me again and I slowly slid down, moving closer to a lying position but not spooning her quite yet. Then the movie did me a favor, the tense ending scene had the girls terrified and cuddling even closer. It was the perfect excuse for me to be scared and cuddle in. I went for it. Pressing my body against hers, my crotch right on her butt. She didn’t even flinch. Her perfect butt against my cock instantly got me hard again. I worried what she would do but I was too horny to care at this point and doubted she would react too harshly to it. What she did next nearly made me cum.

She slowly began to move her butt side to side, in the most faint way so Kate wouldn’t notice. Then she slowly pushed back against me, pushing my crotch against her more. I could feel my cock throbbing at this point. I actually worried I would cum in my pants, that’s how turned on I was. Sadly, the movie came to an end.

“Thank god that’s over” Kate released as she started to sit up. “I fucking hate scary movies.”

“Oh come on, I loved it.” Responsed Ali.

I wondered if she was secretly talking to me.

“Yeah I enjoyed it quite a bit too.” I added.

Hoping she was on my same page.

“Well, I’m exhausted. It’s bedtime.” Kate said and got up. Ali got up right behind her. I stayed sitting, with the blanket on giving myself some time to go down. The girls headed upstairs and after a bit I headed to the kitchen to grab a glass of water before bed.

Suddenly I heard some steps coming down. I felt my heart race hoping it was Ali. It was.

“Hey” she cheerfully exclaimed as she reached for a glass for herself and began filling it by the fridge.

You could sense the sexual tension immediately.

“Hey!” I responded.

Not waiting to push anything I decided not to add any more innuendos on how much I enjoyed the movie.

I finished my glass and awkwardly thought of how to say goodnight to her. She beat me to it. Walked over towards me.

“Thanks again for having me, I’m going to bed.” she said as she wrapped her arms around me, hugging me much tighter than usual. Her scent again driving me wild.

She released and walked towards the stairs. My eyes instantly peering towards her ass in those shorts. She glanced back just as I was staring, winked at me, clearly catching me staring and letting out another, “night” and a smile.