Lorelai: Mother, it's parents' weekend. I'm a parent. That's why I'm here. I'm a parent.
Emily: And I'm a grandparent.
Lorelai: Right. A grandparent, not a parent.
Emily: A grandparent is a type of parent.
Lorelai: No, it's not.
Emily: A grand piano is a type of piano, is it not?
Lorelai: Well, you got me there, Riddler, but I hope that logic works when I crash grandparents' weekend.