You can share the impact with your girlfriend but more importantly, I would talk to these 'friends' of yours and be upfront about their rudeness. They are the ones causing the problem, not your girlfriend.

How long have you been friends with them? It is really surprising that friends would treat each other so poorly. Frankly, I would not even bother to hang out with people like that.

Why would you want to go and be with people who ignore you like that? They are not friends. They are plain rude and disrespectful. Be with people who actually treat you like a friend.