We only know each other online since years ago, we were finally supposed to meet in person next year. Then he suddendly stopped talking to me, and few days ago we had a conversation, he told me he met someone else. Of course it hurts a lot... I thought I should defriend him cause I don't want to have anything to do with him anymore, but at the same time I don't want to be taken as an immature person by doing that.
If you want to save the friendship of what is left of it, then I guess just distance yourself for a while until you can get over him. I'm kind of in a similiar situation and that's what I'm doing.. lol. If things change and he wants a friendship then that'll be up to you but if it's basically a dead end then let it go.