J'ai surpris ma demi-sœur en train de se masturber dans ma chambre

Last week I was getting ready to go to work and I was kinda late already. After my shower I went back to my room to put some clothes and that’s when I found my step sister half naked on my bed wearing one of my shirt and masturbating. I was pretty surprised about that so I confronted her, she told me her fan was broken in her room and it was too hot so that’s why she came to my room. I thought that neither her stepmom or my stepdad would be happy to hear about that so I told her that would stay between us. She started asking me about what was under my towel cause she could see my dick getting hard. I mean come on! I opened my bedroom door to find her with her tits out touching herself of course it would put me in the mood. She seemed pretty happy about it though cause she started touching it before getting on her knees to blow me. Once she got it all sloppy I put her on the bed and started stretching her tight little pussy with my big dick. I fucked her like that for a while,