Details Of The Fight That Sent Demi Lovato To Rehab

01/03/2011 05:12 am ET | Updated May 25, 2011
  • Sharon Cotliar

What really caused Demi Lovato to enter treatment?

The catalyst was a fight between the 18-year-old Disney Channel star and a dancer on the Jonas Brothers world tour, but the problem started the night before, a source close to the singer's family tells PEOPLE.

"As she did on most nights off, Demi invited her band, dancers and her parents to dinner," says the source. "Afterward, she broke off with a very small group."