Love is funny, you know? Sometimes you meet "the one" when you're both single and ready to mingle, and other times . . . not so much. We all know the story of Brad Pitt and Angelina Jolie falling in love on the set of Mr. and Mrs. Smith while he was technically still married to Jennifer Aniston, and LeAnn Rimes's relationship with Eddie Cibrian involved infidelity on both sides. In addition to those couples, there are a handful of other stars who happened to meet their current loves while they happened to be taken — and it's a habit that goes back decades.
Keep reading for 19 stars who went from mistress to main squeeze, then see all the celebrities who can't seem to stop dating their costars.