Worth the wait?

I really like this guy, the problem is he has a girlfriend. We go to school together and got really close the last few months of school. He would hang out with me watching TV until 4am basically everyday the last week of school. Now we are both home in different states for 3 months, but we talk everyday. We text a couple times throughout the day, and then usually for at least a couple hours at night before going to bed. My friends would make fun of us and tell me he likes me because they say the way he acts isn’t normal, but I don’t know. He started dating his girlfriend last winter, and they go to different schools. He rarely talks to me about her, but he had mentioned really struggling with the long distance relationship thing before. Recently he told me they talked about it and said they are both excited for the summer but come August they will have to have a serious talk. I’m conflicted because if he was another one of my best friends and I didn’t like him, I would probably tell him that maybe it isn’t worth it because if he is struggling now, it will only get worse because he has at least two more years of school and she has four, and if he really thinks they might break up in August it’s probably not healthy for either of them to get closer over the summer knowing there is an expiration date. Also, he had a really toxic relationship before this one, so whenever talking about his relationship and why he is with her despite the distance is never that he really likes her, just that they have a really healthy relationship and he likes that. I am not going to say this to him because I do like him and don’t want to come off like I am trying to persuade him to break up with her, even if I think that’s best for him regardless. I just want other people’s opinions on the whole situation because it’s very confusing to me and I would appreciate other perspectives. Sometimes with some of the things he says, I think he might like me, but I just keep reminding myself that he has a girlfriend, and he is a really good guy, so he probably isn’t trying to make it come off that way.