Season 7, Episode 24: "The Invitations"

Then I'll be back.

-So I'm not gonna be an usher? -No.

So I'm nothing?

Jerry is best man, Kramer is an usher, and I am nothing?

-Kramer's not an usher anymore. -What are you talking about?

-You've been demoted. -Why?

Because you called her by the wrong name.

But she really looks like a Lilly.