Katy Perry's makeup artist Todd Delano says that the singer is "always the strong one."

But as her marriage to Russell Brand crumbled during filming of her new documentary movie Part Of Me, the singer found it increasingly difficult to conceal her feelings.

Todd told USA Today that as they travelled around the world on the California Dreams tour, the film crew had unrestricted access including a moment when Katy sobbed backstage in Brazil while holding a necklace Russell gave her.

"The only times she waved the cameras off was when she was dressing," Todd shared. "The cameras were with us, good times and bad."

"She's always the strong one. But sometimes when you hold things in so much, it just bursts. I was like, Cry it out girl.'"

Katy's stylist and longtime friend Johnny Wujek agreed and said that Katy is "so strong, it's very rare to see her weak."

"There's been times I've seen her cry, but never that upset," he shared. "It was the stress of the tour, the stress of no sleep, and then Russell. She just broke down."

Katy says that there was "no way" she was going to reschedule despite how horrible she was feeling.