Brooke Mueller quit rehab because it was "too hard."

The former wife of Charlie Sheen checked in to the Betty Ford Clinic in California last month for her 21st rehab stint but left the facility recently because she was unhappy at being asked to do chores. "Brooke didn't tell anyone, including her lawyer, that she had left Betty Ford. Brooke hated Betty Ford because she was required to do daily chores, which she resented. She complained that Betty Ford was just too hard. Betty Ford is hardcore and Brooke just doesn't respond well in situations where she can't call the shots," a source said.

However, 35-year-old Brooke's decision to leave rehab could ruin her chances at regaining custody of her four-year-old twin sons Bob and Max, who are currently being looked after by Charlie's other ex-wife Denise Richards. "This could have a serious impact on Brooke's bid to get custody of the twins. Brooke just doesn't seem to be taking get sober that seriously. Her doctors at Betty Ford advised her not to leave, but she did anyway. Her therapists will be submitting an extensive report about Brooke's time at Betty Ford and it won't be glowing, that is for sure," the insider added.