Home Gym

My husband has a home gym that my son took over once his father got more busy with work. It’s essentially a garage that is detached from our house. When he’s home from college he will usually be working out. Across the garage is a private pool that my 15 year old daughter and some of her friends use to sunbathe. I started noticing that one of the brunettes girls would silently leave the group every now and disappear for a bit. I caught her one day leaving the garage and had a strange feeling that something was wrong. The next time she excused herself, I went around back while no one was paying attention and peeked through a window and got a good view of her on her knees sucking my sons 8 ish inch cock. I was going to barge in but the sight of this girls hands pulling his foreskin back was making me super wet so I went back inside. 10 minutes had past and I couldn’t stop thinking and wanted to see more. I went back and saw my son railing the hell out of her. As a mother I felt completely jealous seeing this teen girl getting shit faced and spread out on the floor of the gym. I hate that I watched them have sex but I couldn’t stop myself. They kept fucking like bunnies and while they did I rubbed my clit a little. They fucked for a total of 20 minutes before his drenched penis slid out and I caught her readjusting her baby blue bathing suit. My son is an asshole, he will fuck my daughters friends and completely vanish but I have seen one other asian girl get doggy fucked on one of the benches with no condom. I feel like a terrible mother but I haven’t heard anything from my daughter yet.