Quote:
If her friend won't leave, lead the party back to their place or yours, and escalate a threesome.
Lol. And advice for the OP that doesn't assume he's already that good...
Girls alone > groups of three more more > pairs. You are honestly better off going for lone women and larger groups. The problem with pairs is that if you engage the target girl, eventually her friend will get bored and that's where the bullshit and interference come from. If you have to, just run some real surface-level game on the friend, don't be afraid to convey a little sexuality via eye contact. Basically you have to entertain her so that she doesn't go after you. This is a situation where I'm more willing to go for the phone number on the target girl and make arrangements a day or two after.
If you're good enough to follow Arch's advice, do it. If you're not, then go with mine and build up to Arch's.