My name is Philip. I'm 18 years old. I live with my parents and my 20 year old sister Rena. Rena and I both attend a local junior college. I'm majoring in computer science. Rena is majoring in dating and partying. I don't think she is interested in graduating. We commute to and from school by bus. Our schedules match up pretty well so we are often able to ride the bus together.
Anyway, it started on the bus ride home. It was pretty crowded so Rena and I had to stand, nothing unusual given the time of day. I usually zone out on the bus ride home. Rena usually digs out her phone and starts texting. I was standing right behind her. She took me by surprise when she backed up and wiggled her butt against my crotch. My dick leaped to attention.
"What the heck, Rena!" I exclaimed. "Why did you do that?"
"Why did I do what?" my sister responded.
"You know what I'm talking about."
"No, I don't," she said. "I'm just standing here texting my friends and minding my own business." Then she backed up again and rubbed her butt against me. Rena is plenty pretty with a body that tended to be overweight, but sexily so. I think zaftig would be the term used. She takes after our mom that way.
"I'm talking about that...with your butt."
"Incidental contact," she asserted still paying attention to her texting.
"Bullshit," I said.
"It's called chikan."
"Chicken?"
"C-H-I-K-A-N. It's big in Japan. It's where guys grope the girls on the bus or subway, but it can be anywhere else, too. The women and girls mostly just put up with it because they're usually too embarrassed to report it. I saw a couple of videos of it online." I could have pointed out that she was the one groping me, but I'm sure she already knew that. I made a mental note to look up chikan videos when we got home.
"It sounds like it could be dangerous."
"That's why I'm just trying it with my little brother. Don't you like it? You must," Rena continued. "I can feel your stiff dick prodding my butt." This time she moved back against me and stayed there. Shit! I did like it.
"That's not all I'd like to prod," I said and pushed back a little. I was as subtle as I could be. I didn't want us to be seen by other passengers.
"You wish," Rena answered with a giggle.
"If you keep teasing me I may not give you a choice, slut." Would I be willing to fuck my sister? I had to answer yes to that. Would I be willing to rape her? That was a definite no. I knew someone was going to rape her if this was her standard behavior around guys.
"You're talking rape and incest, little brother. That is just plain nasty," she declared. "Maybe you're not as safe as I thought." My statement didn't prompt Rena to move away, though, or even be subtle about it. I took a quick look around and no one seemed to take notice of us or knew we were siblings so I just enjoyed the rest of the bus ride prodding Rena's butt until we arrived at our stop and disembarked.
"I'm on the pill," Rena said as we made our way home.
"Huh?"
"I said that I'm on the pill," she repeated. "I'm on birth control and you wouldn't have to worry about getting me pregnant. Also, I make my sex partners wear condoms. I mean I kind of like the idea of sleeping with you, but having your baby would be kind of weird, don't you think?"
"Are you serious, Rena?" I asked. "I mean a few minutes ago I thought we were just teasing each other. Now you're saying that having sex with me is a good idea?"
Rena nodded her head. "I understand what you're getting at. I guess that makes me a slut. Don't tell Mom or Dad."
"I won't," I promised.
"And I'm sorry about teasing you. Are you serious about wanting to sleep with me?"
"Uh, sure," I responded. "I've had fantasies about you for years. Also, if you hadn't been teasing me, I would never have realized the uh...interest we have in each other."
Rena smiled and took my hand. "I'm glad," she said. "I have a couple of friends who have been sleeping with their brothers for years. They said I should try it, but I was too afraid to ask if you wanted to have sex with me."
"I would have felt the same about me asking you," I said. "Uh, don't tell your friends what we're planning, okay?"
"Okay, if that's what you want," Rena said. We walked into the house and the first thing Rena did was plaster herself against my body and kiss me right on the lips with Mom standing right there watching us. I'm dead meat was my first thought. I think it would be safe to say my sister Rena can be rather unpredictable and impulsive.
"What do you think you're doing kissing your brother like that, Rena?" Mom asked. I couldn't detect any alarm in her voice yet, just curiosity.
"I'm just showing my new boyfriend how much I love him," my sister responded. "I've decided we don't show each other enough love around here."
"He's not your boyfriend," said Mom. "He's your brother."
Rena disengaged from me and then hugged and kissed Mom the same way. "My goodness," Mom exclaimed. "What has gotten into you?"
"Love has gotten into me, Mom," Rena declared. "Now share a kiss with Philip and he can be your boyfriend, too."
"I'm not going to kiss my own son like that," Mom protested. "He wouldn't want me to anyway." I didn't know what kind of game my sister was playing, but I figured I had better play along.
"Why wouldn't I want to kiss my beautiful mother who's also a sexy woman?"
"Did you hear that, Mom," Rena asked. "Philip thinks you're sexy and I happen to agree with him. In fact, if I look as good as you when I'm your age I will be very happy."
"But-" Rena gave Mom a little push into my arms and stepped up behind her sandwiching her between us. I was standing against the kitchen wall so I wasn't going anywhere. I couldn't help it. I popped a boner. There as no question that Mom could feel it, but she was the one looking apologetic. I kissed her gently on the lips. My mother was blushing, but she wasn't trying to pull away either.
"That was nice," Mom said. "Thank you."
"It was my pleasure," I responded.
"I have to get dinner started, okay?" I nodded and Rena got out of Mom's way.
"What was that all about?" I demanded of my sister when we went upstairs. "You scared the heck out of me."