I knew that my Twin Sister was nothing close to a noun, but I'd never have imagined that she could be such a slutty perv. While I was on the way to my room but as passing my twin-sister's one, I saw her fully naked on her bed. Her door wasn't completely closed, like if she expected this to happen. And so it did. I couldn't help but have a look to see what's going on in there and I understood in a second. My twin sister was masturbating on her bed and seemed to have a lot of fun. Knowing what she's been doing had little to no effect on me spying on her to be honest. And actually I started to masturbate too while standing behind her door and trying no to get caught. But at the end I'm pretty sure that this little whore had plan this to happen and enjoyed it even more. I kept watching until she reached orgasm and had one a few seconds later as well.
