Things are getting ugly.

Tarek and Christina El Moussa — the soon-to-be ex-couple and stars of Flip or Flop have a lot more than just a divorce to worry about; insiders exclusively tell In Touch that HGTV is threatening them with a lawsuit — because the network knows the pair is much more powerful together than apart.

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“This is getting really ugly,” a source with the network tells In Touch. “HGTV is livid with Tarek and Christina. Flip or Flop just won’t be the same if they’re not together, so execs desperately want them to reunite to save the show. If they can’t do that, the network wants them to make it seem like they’re getting along, at least until their contract is over. They were given an ultimatum: Either finish out your contracts or we’ll take you to court [for breach of contract]. The network basically said, ‘You guys need to work together, be seen together as a family, walk down the street together.’”

'flip or flop' tarek christina el moussa getty images

And so far, the couple is cooperating — they even spent Christmas together with their two kids, Taylor and Brayden. According to the source, Christina has an ulterior motive — she’s hoping to nab her own spinoff series (though a rep for Christina has denied these claims).

“She wants to cooperate with HGTV because she is gunning to get her own show,” the source explains. “She’s upset because she knows that if she doesn’t cooperate, she might never get her own show, which is now her dream.”

Relive the happier days for Tarek and Christina in the gallery!