tell them to grow up and quit being bitches, or just stop hanging around them if they can't accept that, or better yet tell them to find their own girls without relying on your gf to bring them fresh bait
they're being assholes. not big enough assholes to end the friendship but still assholes. if your gf is sorting them out wioth any of her frinds get her to stop. but dont ditch them as friends, but when you go out and they expect an invite remind them of what they said