Quote from Barney in The Duel
Barney: So, anyway, I was on date with this girl, Jackie.
[flashback to MacLaren's:]
Barney: Wow, Jackie, you make a really great first impression. I have a feeling that tonight you might end up being Jackie... Oh!
Jackie: Yeah, I'm sorry, I'm gonna have to lemon law you.
Barney: It's out there, it's a thing. The lemon law is a thing. Damn, I should have called it Barney's law.