'The Platinum Rule' - Season 3, Episode 11
Ted's upcoming date with his doctor leads the group to explaining why dating somebody you see regularly is a bad idea.
Air Date: December 10th 2007.
Lily: Every time we step out the door they're out there waiting for us! Sometimes we send Ted out as a scout, nobody's out there. We go out a second later, there they are!
Marshall: It's freaking supernatural. Are they ghosts? Can only we see them?
Barney: What rule is there that I can't date a waitress at my favorite bar?
Lily: I don't know, I'd expect you to have one.
Robin: Yeah, with a catchy name.
Lily: We're not gonna date them, we're just gonna be friends with them.
Barney: That's the couple's version of dating.
Robin: And you've got the couples version of the hots for them. You wanna have brunch with them, you wanna go to Pottery Barn with them, you wanna go antiquing with them, don't you? Oh, yeah, you wanna antique the crap out of them.
Ted: This is New York City. We don't talk to the neighbors: we say hello as we pass them in the hall; we call the police when we haven't seen them for a while and there's a weird smell coming from their apartment; and that's it.
Barney: Put a bell around my neck, and scratch my belly, kids, for I am just a docile house cat now. Meow.
Ted: Yeah, I don't have for time for this. I'm out the door as soon as I'm finished with my hair.
Barney: Good, then we have a solid half hour.
Barney: Ted, look at the facts. I dump her, and she says, "no hard feelings." She's a psycho, what other explanation is there?