Boring sex

I’m in my 2nd tri and it’s limited stuff I can do sex wise of course. But while I was just giving my boyfriend head he wasn’t staying up or getting up as fast as I thought. I asked what was wrong and he finally said “it’s just boring”.... I asked him what should I do and he just looked. I just got up and everything was awkward. It’s already a hard time feeling attractive during pregnancy. So at this point idk what should I do. I noticed a lot too that he will masturbate in the bathroom before we have sex sometimes or before I give him head because there won’t be a lot of semen come out. What does this mean? I’ve never experienced this before. I feel so ugly and unattractive or like he’s cheating or something.

Update: I think he masturbates as an excuse to not have sex. He doesn’t do it right before sex. I’ll be in the mood and he knows I’ll ask for it and it’s like he hurries to the bathroom to get off before so being tired will be his excuse.

Update: He also doesn’t shower as much anymore and he blames its because he’s tired but now I’m starting to think it’s because he is trying to avoid sex.