My boyfriend masturbates before getting in the shower while I'm sitting in the next room

(Background info: My boyfriend and I have been dating for over a year and a half. For the 1st couple of months we were having sex pretty much 4-5 times a week. Then it just all of a sudden stopped and we were only having sex like once every 2 weeks and it's pretty much been like that since.) He'll say he's going to take a shower, turns on the water before he gets in, not that unusual I know, then starts watching porn and jacking off while I'm in the next room (I can still hear girls moaning even over the running water and the tv). The 1st time I confronted him about it he got pissed off at me (idk what for) and I told him that i don't care if he does it or watches porn, just don't do it when I'm home. He still continues to do it.. I came home yesterday and he had just turned on the water. What do I hear a few seconds later? Girls fucking moaning. I went to go get something to drink and slamped the door to our room so he will know that I'm home. Still doesn't stop him... I really don't know what to do anymore...