I'm 18 and my boyfriend is 19. We've been dating for almost 11 months. We started dating in September, which is when my senior year started. While I was in school I'd see him 1-2 days on weekdays and every weekend and we'd pretty much have sex every time we aww each other, no matter who was in the house. In June, he got kicked out for a month and had his own place and we would do it even more since we were alone. Then he moved back in his moms house under the condition that he found a job, he said he was stressed and that's why we haven't done it. Now he has a job and says its because there's people always in the house and he doesn't want to get kicked out again. But we used to do it all the time no matter who was home and his mom was aware we were having sex. I try talking to him about it, I come onto him first and he hardly reacts or just smiles and kisses me. And I tell him he doesn't find me sexy anymore. And he says yes I do! Then starts coming onto me, but at that point I feel like he's just doing it because I complain. I don't think there's anyone else, his ex says he cheated on me with her when we first started dating, but I don't think that's true. His sex drive was fine then, I don't know if there's another woman but its unlikely because I see him like everyday and the rest of the time he's working. I don't know what's going on. Help??

I think he is telling you the truth and you're worrying too much. When he was living in his mom's house previously it was under a different set of conditions. Now that she's let him move back in, it seems he's trying to be more respectful of his mother's house, which could include not having sex under her roof.
You don't seem to think he would cheat or is currently cheating so you shouldn't worry about that. His situation in his mom's house has changed and that has very possibly changed his perspective on having sex in her house.

I think backpack2389 is probably right :)
I know how you feel though about not feeling like it counts if you complained first.
I think he loves you or else not having sex but smiling and kissing you when you come onto him wouldn't be a thing.
Hang in there- he is just doing what is right by his mom :)