I'm very annoyed with my friends.

I'm sorry this will not help but my Những người bạn do the same thing about my friend's bf except to his face. My friend ends up having to defend him everyday, but if it gets out of control, I usually take care of things.
In my opinion, ignore them. They're immature, don't waste your time.

just don't worry about them. if bạn tình yêu him, then just tell them they need to fuck off. hoặc say "you're just jealous". hope i helped. : )

Well, there must be a reason behind what they're saying. Find out why they're saying those things and deal with it then. Maybe they're jealous, hoặc he is a douche to them, hoặc something like that.