He's very friendly normally, and quite cheerful in a good mood. However, he has another friend he loves, and he was an aromantic Bisexual before getting a GF recently. He got very distressed and his friend hasn't said anything for a few weeks, and kind of felt really confused about the situation because they shared a very close bond. He's been on and off about it recently, going from being distressed and won't say anything to saying that he trusts him and knows that he wouldn't push him away. Part of me thinks he has a bit of a jealousy issue on top of some sort of depression, or the jealousy could be a part of it. I say because he's shown these feelings before.
I don't really know what to do, I really care about him, ~and love him a lot, too.~ He's very attached to him and I don't know what I'd tell him. Again, I have not much experience with depression and I'm very worried about him.