I'm very annoyed with my friends.

I'm sorry this will not help but my friends 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 you love him, then just tell them they need to fuck off. or 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, or he is a douche to them, or something like that.