What does it mean if a guy I'm friends with goes out of the way to mention his girlfriend?

There's this guy I'm good friends with who is the same age as me (18), we've been friends for 4 1/2 years and we both leave in 5 1/2 weeks for the same college. We dated last summer for about three months starting the weekend of July 4th. After three months we mutually broke it off. About November he got himself a new girlfriend from school who is 2 years younger than him. Within the last month though he has been going out of his way to bring her into every conversation we have, Any time I'm around he says something about her, whether it really fits with the topic of conversation or not, it could be just because he hasn't seen her since school got out about a month ago, I don't know? But at the same time lately he seems he has been going out of his way more and more to hang out with me, Coming and finding me at church just to talk or to ask me a question that anyone could have answered, Coming and sitting by me when our families go out to dinner (which they do about once every two weeks or so) when used to he would go and find my brothers and hang out with them. Last week we went to summer camp his brother and sister and my two brothers and both of us and some other kids from our church group, and while their he would come and sit by me during softball games while other teams were playing or between his turns to bat, and he sat by me or as close as he could to me for classes a couple of times? Yet it seems the more he goes out of his way to spend time with me, the more he goes out of his way to talk about his girlfriend, What's up with that? I could guess all day and ask people I know, but I think I'd like some unbiased opinions from people who may have experience with this sort of thing.