This isn't a shocker.

Luann De Lesseps revealed the incident that caused her to pull the plug on her marriage to Tom D'Agostino on Watch What Happens Live One-On-One, and it's nothing surprising. Basically, her husband was cheating, which is something we've all known all along.

"It was like the weekend before the reunion, basically. Tom went out and he called up an old girlfriend and they met up with a group of people and I didn't know about it. I found out about it the next day in the press, so that for me was the final straw. I was like, "I can't do this anymore,'" she told Andy Cohen.

As for those reports that the reality star roughed up her hubby in a Manhattan restaurant?

"I didn't slap him. What I did was grab his face. It was in the heat of the moment, and I was hurt by something, so I just - I wanted his attention so I grabbed his face, so it wasn't really a slap," she insisted.

We're so sad they split. Their drama was epic!