I know I'm too late but:
Dude. They're just girls. Say something to them, and then either excuse yourself and go do something constructive or see if they welcome your company. If they welcome your company, do something like watch a movie, play some cards, talk to them, or whatever. Girls smell good and they have boobies so try to smell them (without being blatantly obvious) and try to look at their boobies whenever the opportunity presents itself.
That's all you can do. You have a girlfriend so just focus on having fun with your house guests. Personally, I always preferred hanging out with women instead of dudes, anyway. It's a huge ego boost to have all of their attention.








