Kutcher became the frontrunner to take over the lead role from Charlie Sheen after he was fired from the sitcom in 2011 following a public feud with executive producer Chuck Lorre, but Cryer feared he wouldn't be able to get along with his potential new co-star because of their unlikely connection.

The Pretty In Pink actor recalls, "It was a little awkward because she (Moore) and I had dated when he (Kutcher) was seven! There was that aspect, but what happened was, we had our very first meeting... but I didn't know if she had told him we had dated, so for the whole meeting, he didn't say anything, so every time he'd make a joke, I'd be kind of awkwardly like..., 'Ha ha ha, that's a great joke, 'cause we're old friends; it's not like I dated your wife!'

"At the very end of it, he said, 'She told me. It's cool, don't worry about it'."

Cryer, 49, and Moore, 52, dated briefly after co-starring in 1984 film No Small Affair.

The actress was 42 when she wed 27-year-old Kutcher in 2005, but they divorced in 2013.