Julie, my eighteen year old twin sister, was captain of the school volleyball, basketball, soccer, baseball, swimming, lacrosse, football, and track teams, as well as the head cheerleader. Her position meant that she knew a lot of very sexy eighteen year old girls, and that she inevitably became friends with a lot of them too.
Katie was one of Julie's best friends. She was eighteen and only one month younger than Julie and me. She was on most of the same sports teams as my sister. In any other school she could have been the captain of all of them, but there was no girl in our school who could match Julie's sheer athleticism. Katie didn't seem to mind being second best, and I was sure that the two of them being such good friends helped quell any problems they might otherwise have had.
I had mixed feelings when Julie brought Katie home after basketball practice one day. I liked getting as much alone time with my sister as possible, since that usually meant we'd have sex. On the other hand, having two sexy girls around instead of one wasn't all bad. They were both still wearing their tight shorts from practice that showed off their sexy little asses almost as well as if they'd been naked. I was going to have to be patient and wait until later to fuck Julie, but at least I'd have something to watch in the meantime.
"Hey, Jeff," Julie greeted me.
She gave me a big hug and managed to surreptitiously grind against my cock a little without letting Katie see what she was doing.
"Hey, Julie. Hey, Katie," I said, nodding to Julie's friend. "How was practice today?"
"It was good," Julie said. "I think we have a really good team this year."
"Of course we do," Katie said. "Julie's on it. No one from any of the other schools can keep up with her."
"Aw, thanks," Julie said. "You're too modest though. Us working together so well is the real reason our team is so good."
Julie slapped Katie playfully on the butt while winking at me. Katie squealed and clamped her hands down on her ass to protect it from any more sneak attacks. Her face reddened in embarrassment.
"Not in front of your brother," Katie hissed.
"Oh, he doesn't mind. Do you, Jeff?"
"What? Oh, no. I don't mind," I said.
Julie seemed to be actively trying to embarrass both Katie and me. Fortunately she had temporarily had enough with teasing us and moved things along.
"Alright, Katie and I have some homework to do," Julie told me. "We're gonna be in the living room. You can join us if you want."
I watched the girls walk away in their skintight shorts. They giggled as they walked, and Julie made sure to put an extra sway in her step for my benefit. I started to get hard just from watching them. There was no way I could decline my sister's offer to go stare at them some more. I was sure that was her intention from the beginning. Maybe she was just planning on getting me all horny and worked up for later.
Julie and Katie took over the floor of the living room in front of the tv. They were both lying down on their stomachs and giving me an excellent opportunity to check out their asses without being caught. I sat down on the couch behind them.
"Did you want to watch something different on the tv, Jeff?" Katie asked. "We're doing our homework, so it doesn't matter to us what we watch."
I started to answer, but Julie beat me to it.
"You really think he's going to be watching it either?" she asked. "He's got the two hottest girls in school in front of him. I can guarantee that the tv is not what he'll be paying attention to."
Katie shoved Julie reproachfully, though it didn't seem to have the desired effect on my sister.
"Don't talk like that," Katie said. She looked embarrassed again. "He's your brother."
"I'm only teasing," Julie said. "I have to keep him in line, you know."
They soon dropped the subject and got busy doing math problems. Julie, of course, didn't stop teasing me. Once Katie was sufficiently focused on her work that she wasn't paying attention to anything except what was in front of her, Julie slowly started pulling down her shorts. She didn't have any panties on underneath.
My cock hardened in my pants as my twin sister's perfect ass and pussy were revealed to me. It was even hotter than usual because her friend was right there beside her and could look over at any minute. I wasn't sure what would happen if Katie figured out what was going on, but the added risk excited me, and I could tell Julie liked it too. Her pussy juices started leaking onto the floor almost as soon as she removed her shorts.
I couldn't help myself. I whipped out my fully hard seventeen-inch cock and started masturbating. It actually felt kind of weird, and not just because there was another girl in the room. Ever since Julie and I had been having sex, there had been no need for me to get myself off. She was always willing and eager to do it for me.
Julie watched me stroke myself with undisguised lust. She beckoned me closer with her finger. I wasn't sure if I should move since it might attract Katie's attention, but I couldn't say no to my sister. I crawled over to her as quietly as I could.
Julie smiled as her favourite toy got within reach. She reached out and stated jerking me off with one hand while doing her homework with the other. I could tell she was having some difficulty keeping up with Katie, but she had to do her best not to let her friend figure out that she was being distracted by her brother's cock.
After a few minutes of giving me a sneaky handjob, Julie took her hand away. She looked back at me just long enough to put her finger to her lips and make sure that I wouldn't say anything. Katie was concentrating completely on her work by now, and I could tell Julie was planning on taking advantage of that.
Julie used all the patience and grace that she'd acquired from the various sports she played to reach behind her friend without being detected. She carefully slipped her fingers into the waist of Katie's shorts and began peeling them down her thighs. I thought I was going to cum as soon as Katie's magnificent ass and pussy were uncovered. I couldn't believe that neither of the girls had been wearing any panties.
Much like my sister, Katie's butt was perfectly toned and her pussy was shaven smooth. If I'd only been looking at their bottom halves they could have easily passed for twins. I looked rapidly back and forth between the girls' bare asses, almost cumming just at the sight of them side by side.
Somehow my sister actually got away with her little stunt. She finished removing Katie's shorts without the other girl having noticed anything amiss. Julie made sure she had my attention, then threw both her pair of shorts and Katie's behind the couch. The two girls were completely bottomless with no easy was for Julie to fix the problem. I had no idea how she thought she could get away with it.
She lay back down beside her friend and went back to her homework. I had two sexy, perfect asses in front of me and was unable to determine which I should be staring at. Julie solved that problem by grabbing my cock and guiding it to her pussy. She was so wet that a puddle was forming between her legs so I knew I didn't have to worry about whether or not she was ready for me. I was concerned about Katie catching us if I started fucking my sister right next to her, but I wasn't sure that I could resist.
Julie slid the tip of my cock up and down her wet slit. My hesitation disappeared and my instincts took over. I slammed my entire nineteen-inch shaft into my sister's tight pussy in one thrust. She had to bite down on her arm to keep from making any noise as she was suddenly filled up. I was impressed at how quiet she was, since I knew how loudly she usually moaned.
I fucked my sister hard while her oblivious friend lay right next to us. I was no longer afraid of being caught, probably because I was too turned on to care. Some part of me still knew that it could be disastrous if Katie found out what we were up to, but the rest of me was only concerned with getting off. All I wanted to do was pound Julie's pussy until we both came.
"What did you get for number eight?" Katie asked suddenly.
"I, uh, haven't quite finished it yet," Julie answered.
