Where it happened: my bedroom
My sister was always having sleep-overs with her friends. Nothing happened with the other ones but on one sleepover, they stayed up for a while giggling and playing music until after midnight. Then the noise stopped and about an hour later the friend carefully opened the door and snuck into my room. Usually I sleep on my back, but this time I was not asleep but pretended to be asleep. She crept over gently put her hand on my stomach, I guess testing if I was awake. She pressed lightly and I stirred. She put her finger on my mouth like saying shhhhhh. She lifted up her t-shirt showing her gorgeous round breasts, they looked bigger naked than they did under a shirt. I thought all of my sisters friends were cute. She took my hand and put it on her breast, it was very warm and soft. She reached into my pajamas and pulled out my penis which ofcourse was very stiff at this point. She had taken off her panties already, I was laying on my back and she climbed acroos me and lowered herself dowdn guiding my penis inside her. She moved up and down and my penis was sliding in and out. In a few minutes I came, she layed over on me with my penis still in her, and kissed my on the mouth. Then just as quietly, she slid off the bed and left the room.