I (23m) got back home from work early one day. No one was at the house except my sister (18F). When I entered I kept hearing noises so I went upstairs to check it out. As I got close to the door of her room I heard her moaning. I immediately got hard when I realized she was probably getting fucked by some guy. Curiosity really got a hold of me, so I decided to quietly open the door. That’s when I saw her, legs wide open, head tilted back, headphone on, and my boxers in between her legs.
If I’m honest, I actually left those boxer in the bathroom on purpose. I grabbed a pair of boxers I had and jerked off until part of them were covered in my cum. I left them in floor in a way that she could see my pool of semen. I wanted to see what she would do. I checked and they were missing. My sister was masturbating with my cum stains.
She isn’t the only guilty one, I’ve also stolen some of her used panties and done plenty of things with them…
I love her smell and the grool she leaves in them.