We don't know who Alex's one-night stand is on Grey's Anatomy, but we have a pretty good idea who it's not. Here's what TV Guide has to say about one recent rumor ...

Q: Some are saying that Meredith Grey is going to sleep with Alex Karev this spring on Grey's Anatomy. Please tell me it isn't true. I'm totally freaking out about this!

A: First off, we're not going to identify Alex's hookup, but we will help narrow down the list of candidates. You can take a deep breath, because everything will be fine.

Meredith and Derek's marriage by Post-It will not be torn asunder by Alex, and Callie's eyes won't be wandering back toward the men's side of the locker room either.

"Callie and Arizona get a little sexy soon," says Jessica Capshaw, who plays Arizona. "We see a little girl-on-girl action. America was asking for it and America got it."

Man, she knows America well!

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.