When we first got together, we used to have sex multiple times a week, sometimes twice a day. It seemed like he had a higher sex drive than me, and I have always been the one who has a higher sex drive in all my relationships. But after we moved in together 6 months later, it dropped to once a week and has been so roughly for the past year and a half. I've noticed that he watches porn and masturbates every time I leave the house. This has upset me greatly because I'm always willing to have sex or even go down on him without asking anything in return, but he often doesn't seem interested. A couple of weeks ago our sex life picked up when we had a lot of times off together and were working the same shifts. I also noticed he randomly got erections when we were just hanging out and that's not something that usually happens. But now that he's had time alone every day for the past week, he hardly seems interested at all. He told me he thinks he just doesn't have that high of a sex drive, but I don't think that's the case if he's masturbating everyday, even on days that we have had sex. Also, he only ejaculates when I give him a blowjob. He used to ejaculate from sex at first, but he hasn't in a long time. I heard that this can be caused by excessive masturbation, is this true?

I've talked to him about all of this stuff before and he assures me that he still finds me sexy, and that masturbation is a totally different thing for him, but I still worry that it's affecting our sex life. He also doesn't seem as present and aroused when I know he's been masturbating a lot. I don't know if there is any truth to masturbation effecting your sex drive or not, but these are things I've observed and it seems likely to me. I don't know how to bring this up to him because he denies that he masturbates that much and I don't want to make him defensive or feel guilty for doing what's natural. I just want to be able to arouse him like I used to and for us to have the passionate love life I feel like we could have.