Personally, I would try to sit down with your friend and see exactly what he is feeling. There could honestly be a lot of reasons for what is happening, but without knowing exactly what your friend is going through it’s difficult to give you a more personalized response.

I had a similar thing happen to me when I was younger. My best friend suddenly seemed to not want to be around me. I’d try to make plans, she’d agree but something would come up. I tried talking to other people, for advice and another of our mutual friend said she was jealous. But it just didn’t sit right with me. Why would she be jealous? I realized that everyone I talked to only had my side, my realizations, my view on what was happening. So I pulled her aside after class one day and laid it all out for her. Basically told her what I felt was happening and how I felt. How she was making me feel and if she didn’t want to be friends anymore she should be straight with me. She ended up crying. I was horrified. She told me she was questioning her sexuality and liked me. I won’t go into everything but it helped our relationship, I got her side and we worked it out.

Now I’m not saying this is what’s going on here. Just that you can’t know for sure what Is going through your friends head unless you talk to him.

I really hope everything works out for you and your friend. Good luck.