Teddy catches Mark in bed with Reed and we have to laugh at how Mark handles it: He suggests a threesome! Meanwhile, Lexie asks Alex, "Are we a couple? He kisses her and says, "Yeah, we're together. We're a thing."
Owen asks Cristina to move in with him and she plans on saying yes, until Meredith suggests that there's something going on between Teddy and Owen. Cristina demands to know what Meredith knows, but since her information comes from Derek, she can't. Derek warns her, "You can't tell Cristina." Instead, Meredith confronts Owen, telling him, "I know you tried to have Teddy fired and I believe it's because you're in love with her. You will tell Cristina, if you're actually the good guy that she thinks you are."
Lexie is scornful of the Mark's hookup with Reed, but tells Callie. "I'm fine. I do not care about Mark or who he sleeps with." Callie, who's split up with Arizona because of their differences over having a child, tells Lexie. "I keep telling myself that I don't care. And it works, for the most part. But all I want is for her to change her mind and say yes."
Callie catches Mark trying to apologize to Teddy. "Talk to her," Callie urges, except she's not talking about Teddy, but Lexie. "You still love her. The reasons that you broke up aren't reasons anymore. You don't want 50 years to go by and then realize that you let the love of your life get away." He asks why she doesn't do the same with Arizona and she answers, "My reasons are still reasons."
Owen tells Cristina the truth about trying to get Teddy fired, but insists there's nothing going on between them. He explains that his feelings for Teddy are all caught up with his memories of the war. Cristina wants to know if he's in love with Teddy, but all he can say is, "I don't know what I feel for Teddy. But I do know what I feel for you. I shouldn't have to explain myself to you," he says. They hear a pager go off: It's Teddy, who's heard everything!
Miranda makes Ben swear to keep their relationship a secret from the hospital staff, and forbids him from flirting with her at work. But she doesn't expect to catch him flirting with a pretty nurse! Ben explains that the only reason he flirts with the nurse is so she'll give him good schedules. "That's bad flirting. For you, whom I actually like, I break out my A game. Because I mean it. I'm in this for real," he assures her and she drags him into the elevator.
We gasp when Mark tells Lexie, "I'm still in love with you. I tried not to be, but it didn't work. Sloan's gone. There's no baby. And I don't want to sleep around. I want another chance."
Lexie is thrown, but tells him, "I have a boyfriend." "I know, I'm telling you, you can have a husband," Mark says. She tears up, but when Alex arrives, she leaves with him.
Arizona and Callie meet in the elevator. They kiss, but Arizona walks away before Callie can say anything.
Cristina tells Meredith, "I'm not moving in with Owen." Meredith shows her the blueprints for the house she and Derek are planning and tells her one of the rooms is for her.