Scott Eastwood Reveals Shocker About Ashton Kutcher & Demi Moore's Divorce

'The Longest Ride' star drops a major bombshell about what may have led to the couple's split.

The Longest Ride
star Scott Eastwood dropped a major bombshell about what may have led to Ashton Kutcher and Demi Moore's divorce.

Things got interesting on Thursday's Watch What Happens Live when a caller asked fellow guest Jon Cryer if it was awkward working with Kutcher on Two and a Half Men, since they had both been in relationships with Moore. Cryer dated Moore in the 1980s, while Kutcher was married to her from 2005-13.

VIDEO: Jon Cryer on Dating Demi Moore in the 1980s

"Yeah it was a little awkward I have to say," Cryer, 49, began to answer, before Eastwood chimed in with his own shocking revelation.

"If it makes you feel any better, he did sleep with one of my ex-girlfriends -- but she was my current girlfriend at the time," Eastwood said.

"Wait, he slept with your girlfriend while you were together?" probed Watch What Happens Live host Andy Cohen. "How did you find out about that?"

RELATED: Ashton Kutcher Has No Interest 'Being the One-Night Stand Guy'

"Well, I think it was the catalyst that broke him and Demi up," Eastwood said, referencing the couple's late 2011 split.

Cohen asked if Eastwood's girlfriend at the time was one of the two girls at the center of the infamous San Diego incident that Us Weekly reported back in 2011, and the 29-year-old actor confirmed that it was. He revealed that he and one of his friends were dating the two girls at the time.

"Mmhmm, yeah, scandal," Eastwood said before taking a drink.

If you thought Eastwood was angry at Kutcher over the incident, you'd be wrong.

"No not at all," he said when asked if he still harbored resentment toward Kutcher.

Still, this is one revelation that is just too juicy not to talk about.

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Eastwood stars in the romantic drama The Longest Ride, which hits theaters Friday. ET takes a look at what makes Nicholas Sparks' big-screen adaptations box-office gold, below!