Credit: Gregg DeGuire/

Brooke Mueller didn't see it coming.

After Charlie Sheen unexpectedly filed for divorce on Monday, an attorney for the actor's wife says she feels betrayed.

"Charlie humiliated Brooke," lawyer Sorrell Trope tells TMZ, claiming that Mueller, 32, wasn't given a heads up about Sheen's decision to file.

Trope says that the estranged pair signed a property agreement in May, but agreed to wait another year before filing for divorce. Why? "She didn't want to make trouble for Charlie," Trope explains. (In the spring, Sheen, 45, was on trial for allegedly attacking Mueller.)

Citing "irreconcilable differences," Sheen seeks joint legal and physical custody of their twins Bob and Max, 19 months; Mueller responded on Monday by filing for primary physical custody and joint legal custody.

Trope added that Sheen's move was especially hurtful given Mueller's public support of the star after his recent NYC hotel drama. She told Extra: "Charlie is a survivor. He knows how to handle himself."