Derek: The divorce is my fault, let me take responsibility.
Addison: We both had affairs.
Derek: You had a one night stand with Mark.
Addison: Derek, actually ... it was ... it was ...
Derek: It was two nights. You made a mistake. Meredith and I, we had a relationship.
George: I thought we were all done with the whole muffin thing.
Izzie: This isn't muffins. This is breakfast.
Meredith: Are you okay?
Izzie: Of course I’m okay. I’m a millionaire.
Derek: (to Meredith) You look, uh, good without an appendix. It suits you.
Derek: Hey, you know what I like? I like that we're civilized. We're these adult grown people who can be divorced and friendly. We deserve a medal.
Addison: It wasn't a one night stand. Mark and I. It wasn't a one night stand, I was in love with him. Or at least I thought I was. After you left we lived together for two months. I wanted to believe that we could make it work, that I hadn't thrown my marriage away, that I hadn't thrown my life away on a fling. But he's Mark, and, well, I caught him with someone else, and then Richard called, so ... We both had relationships with other people. We're both equally liable for everything. So please, take the Brownstone.
Derek: All I want is Seattle. I want Seattle, and I want never to see you again.
(before the M&M)
Cristina: George, Alex, you guys go get the seats, Meredith and I'll get the snacks.
Episode Title: Oh, The Guilt
"Oh, The Guilt" is a song sung by Nirvana written by the late Kurt Cobain.