Teddy introduces Cristina to her patient, Ruthie, who is charming and sweet and shockingly, Cristina is actually incredibly pleasant back. After a few moments, though, her good cheer starts to fade. Ruthie, while sweet, wants to go over all of her allergies, and this turns into her worrying about every little thing including dust mites in her pillow, and she asks to have a new nurse. All of this still doesn't prepare Cristina for where Ruthie goes next, which is saying she's worried about her new mechanical valve making a clicking noise. Cristina immediately tries to brush off her doubts since switching up and using a porcine valve would be a whole different procedure than what they planned, but Ruthie is really into the idea of a pig. Teddy watches with bright-eyed amusement as Cristina is finally left speechless by Ruthie's musings.
Addie, joined by Arizona, gets down to work and sees the same thing everyone already has, but she does a better job explaining more thoroughly that as the baby grows, the bands will cut off the circulation and possibly result in the loss of the right leg and bad damage to the left. I guess Sloan is 22 weeks along and Addison warns that surgery now could be risky, but Arizona says that it wouldn't kill the baby if they just left it for now, and that they could fit him with a prosthesis after birth so he could most likely walk one day. Sloan completely freaks out at the idea and Mark tries to calm her down. She then throws the room for a loop when she asks which one of the ladies Mark slept with. Arizona quickly absolves herself and Mark explains to a rather horrified Addison that he and Sloan had been bonding. She points out that talking about one's sexual exploits isn't the generally accepted method for that, but Sloan just wants to be sure he didn't get Addison pregnant and then leave her alone and wanting revenge. On paper, as I type this, it sounds like we're supposed to realize all of Sloan's trust issues and maybe cut her a break for being a boorish, snotty pain in the ass but I have to say, I'm totally not there. I still find her a pill without any redeeming qualities and think that by now her attitude might have helped balance some of the guilt Mark is feeling over the situation and made him a bit less gullible, but it doesn't seem to be the case. Addison just assures her that they hooked up a long time ago and that she's going to do everything she can, so Sloan decides she wants the surgery right now.