Cristina: What happened to Hahn? Whatever made Hahn leave, it can be fixed. ... Unless she was fire-- She wasn't fired was she?
Callie: She's not coming back.
Cristina: You don't know that.
Mark: She kinda does.
Callie: Because she doesn't... It's just too... We had a fight.
Cristina: Please. Meredith and I fight all the time. We still work together. It's not like Hahn was your girlfriend or something. ... Oh my God. She was your girlfriend?
Callie: Look, we hadn't figured it all out.
Cristina: Wait, so are you a lesbian now?
Mark: I dunno... maybe you were a "once-bian."
Callie: Or a twice-bian. Whatever. It's over.
Cristina: Are you okay?
Mark: She's fine. Leave her alone.