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 says.
"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."
The following day, tour managers and Lovato's stepfather, Eddie De La Garza, questioned the group's conduct. According to a source close to the situation, the group had been partying.
"When tour management found out about this, they talked to the people involved, including Demi," says the source. "Demi reacted badly and perceived that someone on tour had told on her."
