What Leads To Prostate Masturbation?

I ve been with my boyfriend for almost two years, threw are relationship we have split up a few times. The longest split up was about two weeks. When I came back When we went to bed that night It takes me a minute to fall asleep he always falls right out. But on the night I came back after we turned the lights off and are room is pitch black so you can t see a thing, I noticed the bed was shaking I just thought he was enjoying himself didn t care fell asleep, but this was happening every night all night long to we re I sometimes would be woken up or it would keep me awake. Having to go to work everyday it became annoying so I confronted him he denied it got so angry at me and the tension was on. So it still continued till one night I thought well if I put my arm around him to hold him I ll feel his hard on and then he can t deny it, so I did but he wasn t hard so then I was like what is he doing. I knew about prostate masterbation but with his ego I never would have ever thought he was doing this. So I started investigating his body when I would watch tv in bed the light would be bright enough to where I can see his whole body. He lays on his side with his legs together but he dose it so discreetly to the point where nothing shakes not even the blankets but when I put my hand on the mattress I can feel him doing something. This is the position he always dose it. I confronted him again and he got so angry he told me I must be on drugs Im crazy and kicked me out of his house, it s one in the morning. A week later I came back and thought maybe he had stopped no it s gotten worse he has got a little vibrator I can hear it a little bit one of those silent kind but every night all night long I think he keeps the vibrator in all day an Like I said I study him an notice different little things and now the entencitied has got ton bad and it s like he dosent even care if I m right next to him. So most of the time in the middle of the night I go sleep on the couch and then I feel the house vibrating cause he s in there just going at it cause he don t have to be so discreet cause I m not in there and at the beginning of are relationship if I ever fell asleep on the couch and wasn t in bed with him he would get so angry now when I leave the room to go to the couch it dosent bother him at all. And once again we split up and I left cause I couldn t take it no more. I asked him to please put his toy away so I can sleep he turned the light and told me to give him his keys to the house and get out. It hurts so bad cause I thought he Loved me but he can t possibly Love me anymore. It s hard to live cause Love hi but I look at the big picture and tell myself I can t fix something like this. What should I do?