Luke: You were never supposed to tip me, anyway.
Lorelai: What?
Luke: I'm the proprietor. You're not supposed to tip the proprietor, even when they serve you.
Lorelai: You mean all those years, that extra 20% was unnecessary?
Luke: You never tipped me 20%.
Lorelai: Ooh. Now it's getting ugly.
Luke: You were a solid 15 percenter, sometimes less if the bill got higher. Way less if you were mad at me about something.
Lorelai: Well, it doesn't matter. I wasn't supposed to be tipping you, anyway.