Hey man, I've had a similar experiences, so much so I've gotten quite good at responding to them. You should have walked over and taken control of the situation (
displaying dominance and confidence) and said "whats a guy got to do to get an introduction to a girls friends around her?" (with a smile). The guys wont know how to react to this obstacle so you'll be in charge. Ignore the girl for a minute or so, talk to the guys, JUST THE GUYS. This reinforeces your dominance, social proof, and even makes her want you to talk to her. Maybe after a few minutes just turn to her and say "lets go find some place quiet", tell the set you're stealing her for a while and leave.
Lemme know what you think dude, if it would have suited the situation, been an improvement or whatever
GrifterUK