How I Met Your Mother Season 3 Episode 11: "The Platinum Rule"
Ted asks the dermatologist removing his butterfly tattoo on a date. The gang tries to talk Ted out of going out with someone he's going to see regularly (aka The Platinum Rule). Everyone shares their horror stories.
Robin: We can split a cab to work together, we always have a standing lunch date, and last night, at the hockey game, Curt got us into the locker room and I met Mason Raymond. [gang looks clueless] Left wing for the Vancouver Canucks! Barney: What's the opposite of name-dropping?
Ted [showing his tramp-stamp]: Say goodbye, kids, 'cause it won't be around much longer. Lily: Oh, but Ted, if you get rid of the butterfly how's everyone gonna know you're a stripper from Reno with daddy issues?