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). True, no one broke up or made up this week, but that doesn't mean the relationships aren't being tested... On, With New-Found Concerns: Derek and Meredith Remember Derek's laissez-faire attitude not long ago? Where did that go? Now he's not so sold on the "ignorance is bliss" idea when it comes to Meredith being at risk for Alzheimer's. She's being forgetful lately — though perhaps no more so than anyone — and Derek is practically developing ulcers with his worrywart-ness. On, With Insecurities: Callie and Arizona Calzona might be pretty solid, as relationships on this show go. But Callie's still feeling self-conscious about not living up to her girlfriend. She came to the lesbian party (fashionably) late, and now she feels like she's paying the price for it. And it's no wonder, considering her relationship with Erica ended because she felt Callie wasn't "lesbian enough."