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

Hi, everyone! My ex and I dated for three years, broke up last August and recently started hanging out again. We haven't discussed getting back together, but we kind of fell back into it. I still enjoy his company and have been spending the night at his place a few days a week. 

I am a little conflicted is because he only texts me at night right when he's ready to go to bed. It's not even like a booty call - we just cuddle up and go to sleep. I've texted him about hanging out four times in the last two weeks, during the day, and he said he couldn't all four times. He has his friends over almost everyday, female and male, and he will only text me after they're "done" hanging out and he's about to go to sleep. I've met all of the people he has over so I don't think he's embarrassed of me? I even hang out with some of them on a regular basis. Or maybe I'm just boring?

Also, we live in the same apartment complex. I saw his female friend's car outside his place at 6am when I was leaving for school the other day - one of the days I hadn't stayed over. It made my heart sink, because I felt like maybe I wasn't the only girl he's been spending the night with. I am going to ask him about it before I jump to any conclusions but I have decided that if she (or anyone else) did spend the night with him, I won't be seeing him anymore. 

Anyway, I would really like advice on how to bring up the "only hanging out at night" thing. It just doesn't sit right with me, but I am not super sure why.  It's not like around waiting for him to text me all day - I'm pretty busy with school, clubs, friends, and such, so I don't even know why this is bugging me. I don't know how to articulate these feelings. Would you be bothered by this? Does it seem like a red flag?
<bot>: My ex only invites me over right when he's about to go to sleep. Should I be bothered by this and should I bring it up?