Flip or Flop's Christina El Moussa has been hiding her pain for years while dealing with estranged husband Tarek El Moussa's ugly behavior and wild mood swings.

Now, an eyewitness reveals his most disgusting assault yet. In front of Flip or Flop’s crew, the HGTV star threatened to rape Christina. He intended it as a joke, says the eyewitness, but it left those who heard it appalled.

MORE: 'Flip or Flop' Star Christina El Moussa Moves Forward With Plans for a Spinoff

He told the mother of his two children, “‘Shut up, woman, or I’ll rape you.’ He actually joked about raping Christina on more than one occasion. Tarek thinks it’s funny,” the eyewitness shares. But no one else thought it was, and the crew did their best to shield her from him.

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In fact, Life & Style has learned that there was even a discussion last spring during which “the crew was asked to be efficient with takes so that there was no downtime for Tarek and Christina on set,” the source recalls. “When there’s downtime, bad things happen.”

Christina eventually learned to seek refuge from Tarek in her car during filming breaks. But the 35-year-old was hard to ignore. “One time, he went up to the car and pounded on the window,” the source shares. “Christina locked the doors.”

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Tarek’s low points were “a huge factor in their marriage falling apart,” says an HGTV insider. “Christina hit a breaking point and couldn’t stand to be around him anymore. She fell out of love.”

As In Touch first revealed last week, Tarek constantly tormented and mortified Christina on the Flip or Flop set, calling her a “whore” and grabbing her chest and butt in front of the crew.

For more updates on Tarek and Christina El Moussa’s divorce, pick up the latest issue of Life & Style, on newsstands now!

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