Credit: Ron Tom/Getty Images Photo: Mark Sloan and Callie Torres
Like any great show, the relationships on Grey's constantly have us on our toes. Here's a recap of the latest couples going strong, the couples dying slow, painful deaths, and the couples whose love has been brought back to life (for another episode at least).

On, as Professional Rivals: Teddy and Derek
No matter what accord they may have reached by the end of the episode, Derek all but bared his teeth to Teddy and made a new "frenemy" out of her when he blamed her for Cristina leaving the program. Maybe Derek caught wind of the not-so-nice things Teddy said to the Chief about Neuro?

Off, as Romantic Interests: Alex and April
It looked as though April was about to get her wish and have a romantic interlude with her newfound-crush Alex. But Alex was more interested in an easy lay and was cavalier about it being April's first time. He got all exasperated and left in a huff, leaving April partially undressed and completely traumatized.
(Did you think the fight between Karev and Avery was hot? Vote in our poll!)

On, as Allies: Derek and Cristina
Derek totally sandbagged the others' doctors intervention efforts when he went to Cristina's place early and ruined the surprise. The two of them escaped to the roof and spent hours mulling over interior design choices: a productive conversation but not as productive as Cristina figuring out her future.

On, as Roomies: Callie and Mark
Sure, she might have been sauced at the time, but Callie still popped the question to Mark. Not the question, but rather a proposition to live under the same roof. It makes sense: they're best friends and they're always over at each other's digs all the time anyway. But are they ready to cohabitate? Will the proximity harm their friendship? Will the toilet seat drive a wedge between them? Looks like they'll be getting very close on the next episode...

MORE ON GREY'S RELATIONSHIPS:
Spoiler: Who’s Bailey’s New Squeeze on Grey's Anatomy?
Poll: Is Callie Better with Mark or Arizona?