It’s not just their kids that keep Tarek El Moussa and Christina Haack together since the successful home-flippers ( Flip or Flop) went their separate ways and got remarried. The two are back for more real estate ventures on The Flip Off, a throwdown competition that airs Wednesdays on HGTV.

Christina Haack (formerly Christina Hall) shared a shocking truth about her past relationship with ex-husband Tarek El Moussa, and revealed that his mother, Dominique El Moussa, told the HGTV star that she should reconsider marrying her son.

Christina Haack and Tarek El Moussa split close to 10 years ago—but the mother of three still knows how to get under her ex-husband's skin. She displayed that skill in the latest episode of their HGTV show " The Flip Off " when she teased a "new partner" who she knew would spark some upset.