Lo and behold, Katherine Heigl's Izzie Stevens is actually appearing on Grey's Anatomy this week! That's good news for fans (well, most fans), but not for Alex Karev.

Izzie's husband has just slept with someone else, as we saw in "Blink," and someone we know, no less. One gets the impression that this isn't going to end well.

In this preview clip from "I Like You So Much Better When You're Naked," Meredith comes in to tell Alex that his wife is coming back to town, and finds him, well ...

[video url="http://www.tvfanatic.com/videos/i-like-you-so-much-better-when-youre-naked-preview-1/" title="I Like You So Much Better When You're Naked Preview #1"] [/video]

Follow the jump for another clip from the episode, featuring a tense Izzie and Alex reunion. She wants to resume a normal life together and look for jobs nearby.

As for Alex? He doesn't wanna have some big talk ...

[video url="http://www.tvfanatic.com/videos/i-like-you-so-much-better-when-youre-naked-preview-2/" title="I Like You So Much Better When You're Naked Preview #2"] [/video]

What do you think of these two Grey's Anatomy clips? Is Alex's cover going to be blown? Will he spill the beans himself? Is their marriage doomed?

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