Concerned for my relationship

Hey okay so me and my boyfriend have been staying together for a little over a month now and I’ve caught him masturbating and I’ve spoken with him about it and let it be known that I felt some way because he’s done it while I was here in the other room. So I just caught him doing it again today in my bathroom (but he doesn’t know) and i feel like if he wanted to have sex so bad we couldve done it. It’s to the point where he’ll tell me he has to go to the bathroom just to do it. I just feel like he don’t be wanting to have sex with me sometimes he’ll rather masturbate instead but I don’t know but why look at other people having sex when you gf/bf in the other room and you can do it with them. Then I’m a little slim and I have a butt but not as big as how the girl in the videos he watches so I definitely feel like I not enough for him sexually. Am I wrong?