I live in a fairly wealthy family. We're not carefree by any means, but we don't have to worry. And I'll admit it, people with money are strange sometimes. My father is the vice-president of a company, and we live in a really nice neighborhood. Our house is big but not lavish, but it's more than enough for the four of us, including my sister Sara, who is two years older than me. She has long bleached hair, and a nice tanned, tight body. And back to my point about people with money, we're a lot different than the other families around us. We don't have dark family secrets, we don't lie to each other or squabble constantly.
In fact, we all get along really well. My parents are very open with us, and my sister and I were unusually close. Even after my parents gave me the sex talk, my sister told me all of the things they left out, like all of the positions and various activities people did during sex. I always felt close to her, and she genuinely liked me. Sometimes she would come in my room just to be around me, and we would listen to music or talk.
As I neared eighteen, Sara started joking around with me about sex. Sometimes she would come into my room without knocking, to see if I was jerking off. Stuff like that, she was just playing around. Once I was eighteen, and I felt like I could do anything I wanted, I decided to pull that prank on her.
Our parents left for a business trip, and we would be alone for a whole week, and I knew that Sara would occasionally sneak boys up to her room. I never really gave it another thought, I guess I just assumed she was having sex, and it wasn't a big deal. I wasn't going to tell our parents, my sister and I trusted each other.
But one day, late in the afternoon, I waited until Sara had been in her room for a while, and I figured I would burst into her room. So I snuck up the stairs to her bedroom and listened through the door. To my delight, I heard distinct sexual sounds. She must have been masturbating, I was so lucky! I quickly opened the door.
Sara was on all fours on her bed, naked and facing me with her eyes closed, and to my surprise there was a skinny young man not much older than me slamming into her from behind. I just froze, I had not expected to find Sara fucking someone in her room. She opened her eyes when she heard me enter, but she didn't act embarrassed or angry. She kind of smiled at me while I just stood there. The guy stuffing her didn't let up, he looked questioningly at me, and then down at Sara.
"Who's this?" he asked casually.
Sara seemed to really be enjoying herself, and she was obviously approaching an orgasm. Her face contorted a bit.
"My brother," she answered.
The guy kept slamming her, unaffected by my presence. I just stared as he pumped into her, and after a few moments Sara squealed and gripped the bed tightly. She lowered her face into the mattress and cried out into the sheets as she came. The guy was not far behind, and he soon grunted and hunched over her as he shot deep inside of her. After a minute of catching their breath, Sara looked up at me and smiled.
"Hey," she said. "Don't just stand there, come over here."
I cautiously approached the bed. The guy leaned back against the bed, and Sara sat up on her knees. She pulled me over to her.
"You got quite the show," she said.
I didn't know what to say. I felt weird with the guy who I didn't know laying naked next to me. He probably felt the same way, although fucking my sister in front of me didn't seem to bother him, so he pulled the condom off his dick and got dressed and left quickly.
"He comes over once in a while," Sara said.
