Friends. Specifically friends of the girls that I hit on. I'll strike up conversations with women and as things are going swimmingly, her friend comes over, grabs her by the arm and says, "Come on, we're going home/to x bar/over here."

This happens to me 9/10 times I'm talking to a girl and I've tried everything, taking the girl away from her friends, involving her friends with conversation, but NO MATTER WHAT once I get to the point where the woman I'm interested in is in my pocket, some cock-blocking bitch (usually quite drunk) stumbles over and drags her away from me. Dammit, some of these women I've met were awesome!

Halp.