Who is Made For Each Other (MFEO) on Grey's Anatomy? Shonda Rhimes responded to that very question recently - and spelled out that LOL-tastic acronym in the process.

We know Meredith and Derek are hitched and trying for a McBaby, so the question was geared toward some of the other couples on GA. Shonda offered this Calzona report:

“I’ve always said that Callie and Arizona are MFEO - Made for Each Other,” she said. “And that still holds true.” But, before you commence celebrating, there is bad news:

“They are going to go through hell before they get to any sort of [semblance] of a happy ending,” she said. “If they were just happy, I don’t know who would be watching.”

She does make a point. Still no comment on whether Callie's pregnant.

As for Mark and Lexie, are they similarly MFEO? “There will be a new wrench in the works and they will have a new run at happiness,” Rhimes told TV Line's Matt Mitovich.

“Right now, I don’t want to say which one comes first.”

Let the speculation - and comments - continue!

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