My Not So Little Sister

I don't know where else to tell this, but it's been eating me alive. My parents sometimes leave on the weekends to stay at a timeshare. We usually can't go because we have things after school like robotics club.

My sister and I don't really do much together when our parents leave. One night, I went to bed as normal. I woke up because I heard some noise. It was like 2AM. I peek out of my room and notice my sister still had her light on. The creaking noise still wouldn't go away. Now I can hear moaning.

I tip-toe to her door and find that it's a bit open. When I looked inside, I was so shocked. There was my sister on her back, legs on the guy's shoulders, and he was giving it to her real good. He speeds up his pounding, I can see my sister's tits bouncing. She lets out a deep moan before trying to push him away. He pulls out of her and she's still twitching. He climbs up to her face, then she blows him until he pulls out again to cum on her face.

He gets up, grabs her shirt and throws it at her. While she's wiping the cum off her face, he pulls out his wallet from his pants and sets some cash on the small table next to her bed.

I guess that's how she can buy all that stuff from Amazon all the time. And maybe that's why she sometimes looks so messy when we get picked up after our after school activities.