Search Results: many regular guys have girlfriends

I have known this guy for years, but we never really hung out much before this year. We were really excited this summer when our favorite tv show came back on and decided to binge watch the previous season, as well as the current season together. This all led to us spending weekends together and daily texts for new theories/news about what would happen to our favorite characters.
After the show ended things slowed down some, but we still text at least every couple days, and spend most weekends together with friends.
Before all this we never hung out just us. We do occasionally though not often, and lately he has been asking me to come over and hang out with him and his roommates often (they both have girlfriends, and sometimes they are there) without inviting our mutual friends. Also we spend enough time together that we have taken to just sharing drinks fairly regularly so we don't have to leave the couch.
He doesn't always sit next to me though and doesn't seem to mind when he doesn't. When he does though, it's almost like he's sitting on top of me he is so close. He never makes more physical contact than that (other than EVERYTHING is a reason to high five), even though he gives most of our female friends hugs goodbye.
He has introduced me to most of his friends and at this point thinks I know everyone in his life, and I seem to have open invitations to most things he does on the regular with certain friends. But if he seems to spend a lot of time singling me out while we are with others he will just up and leave me for a while. I just can't tell what's up.