Chemistry is always a good thing. And in the world of Hollywood, that means ratings, viewers, and money. Actors and actresses will take on any role if the contract and pay is right for them.

Even if that means playing the sibling of your lover off-screen. It may be weird to some but these men and women are professionals, able to set aside any personal feelings once cameras start rolling.

Here some of the more memorable couples who dated in real life, all while playing siblings on a show starting with Selena Gomez and David Henrie. They reportedly got together after Gomez split from Justin Bieber.