Ellen Pompeo, Patrick Dempsey Ellen Pompeo, Patrick Dempsey

The Grey in Grey's Anatomy is about to face pregnancy hormones head on — and for Derek, it's both a blessing and a curse.

Meredith (Ellen Pompeo) will be dealing with her uncontrollable mood swings this week, which will go from sexy to angry and crying within a moment's notice. Still, on the plus side, at least Derek (Patrick Dempsey) doesn't have to yell at interns — Mer will take care of that for him!

Check out an exclusive sneak peek at this week's Grey's Anatomy:

Grey's Anatomy airs Thursdays at 9/8c on ABC.