Tarek El Moussa Allegedly Goes Off on Ex, Christina, on 'Flip or Flop' Set - TMZ

Tarek El Moussa flipped out on his "Flip or Flop" costar and ex-wife, Christina Haack, for letting him know it was time to film ...

We're told Tarek immediately lost his cool and went on a verbal tirade directed toward Christina ...

Our sources say Tarek boasted that he "made" Christina and called her a "washed-up loser," and exclaimed that he enjoys watching her fail.

this isn't the first time Tarek went on a tirade against Christina on set.