You’ve just met a girl, and you like her, and you’re getting to know her, and then, all of a sudden, out of nowhere, a man you’ve never met before in your life steps up to you and starts talking to you.
“Hey, how do you guys know each other?” he asks.
Or, “Dude, where’d you get that shirt – it looks like something I saw at a yard sale last weekend,” he remarks.
Or, “Hey, buddy – that’s my friend. She doesn’t want to talk to you.”