<human>: Can you condense the text into a few key points?

My boyfriend and I live together. Recently once a week or so he will stay out all night and come back the next morning. He says he partied at a friend's house and just stayed over. I know he is very comfortable with crashing at people's places, and did this often before we dated, but I find it suspicious because we live where Uber is pretty cheap. We have lived together for 8 months and he never used to do this after partying, because he would just take an Uber home at 2 am or so for 5-10 bucks. He doesn't drive and takes Uber often.

Our relationship hasn't been that strong lately and we don't have sex very often. The sex problem is caused by our different sleep schedules; I pass out at 12, he passes out at 4 am because he works at a bar till 2 am most nights.

According to mutual friends he often cheated on old girlfriends, but I've never had any proof he's cheated on me. I'm not sure how to proceed because it could just be misguided speculation. Looking at his texts seems invasive, and confronting him seems like it would be jumping the gun. Thanks for the advice and speculation.
<bot>: Boyfriend may be cheating on me based on him not coming home once a week and our poor sex life, but I have no proof.