Sure, it was a little weird that Michael C. Hall and Jennifer Carpenter played brother and sister on "Dexter," but fell in love in real life and got hitched. Still, we loved them as a couple. They were the kind of cool duo who bantered with each other during interviews and stared at each other on the red carpet with adoring, serial-killer-what? googly eyes. Not to mention that they made it through Michael's battle with Hodgkin's lymphoma. So we're sad to report that they have filed for divorce and have been separated for months. Ironic, since the two of them had to attend the "Dexter" season finale party just this week. [People]

No matter how many times we tell them it's risky, TV show stars keep falling in love with each other—knowing full well that if it doesn't work out that they're stuck working with their ex for ... years. Here are a few casualties of co-star breakups.