Your best friend finding a new best friend hurts. It doesn’t erase what the two of you had.

Watching your closest friend get close to someone else is a real loss, and it is allowed to hurt without anybody having done wrong. The part that stings most is the rewriting: it can start to feel like the years you had were never what you thought. They were. Friendship is not a single seat that somebody else is now sitting in.

Give yourself permission to be sad about it without making it a case against them. If the friendship still matters, say one honest sentence rather than going cold. And keep taking the invitations that come from elsewhere.