A mom of 3 was torn about whether to move in with her ex-husband but made the decision based on 'what's best for their kids'

• Katie Mathis, a TikToker, posed a viral question: Should she move in with her ex-husband and his new wife?
• Viewers were divided, saying it was economically wise but could be emotionally challenging.

On Monday, Katie Mathis, a 33-year-old influencer and photographer, took to TikTok to ask what would become a fiercely contentious question: "My ex-husband and his wife just invited me to move into their house with them," she said. "What do I do?"

Spoiler alert: Mathis is set to move on Friday, telling Insider she was taking the plunge after careful consideration because the arrangement would provide a more consistent environment for their three daughters, and her relationship with her ex was healthy.

She said she'd be residing in a tiny, detached apartment next to her ex's house. "It's better to do this together," she told Insider.

But Mathis' query, which has 2.1 million views, fiercely divided viewers. "In this economy? Absolutely," one wrote in support of the decision. Another said: "As a child of divorced parents with constant moving back and forth this would have been amazing!"

But others didn't take to the idea that Mathis would be relegated to a tiny home on a property where she'd formerly resided with her ex. "Too many conflicts of interest and room for issues to pop up — finances, emotions," one viewer warned.

In a subsequent video weighing the pros and cons, Mathis said she was concerned about downsizing from the 2,800-square-foot Nashville home she owns into the 500-square-foot studio. But she planned to rent out her own home for passive income, she said, adding that she could always move back if things don't work out.

At the end of her viral video, Mathis films her ex-husband — the retired NFL player Evan Mathis — pulling up the driveway. "When you moving in?" he asks.

Mathis said the trio was laying out all the logistics in a big binder

While her relationship with her ex and his new wife has been inconsistent over the years, "we are just getting along so well right now," Mathis said. She added that her own partner of one-and-a-half years is fully supportive of the decision.

Mathis told Insider she'd actually made up her mind about the move before bringing the question to TikTok but wanted to harness the virality to help others.

"I want to show people how you can have disagreements with your baby daddy or co-parent yet still hold yourself high," she said. "Our kids do not think we have disagreements. They do not think that we fight."

She said the future housemates were also looking to minimize any potential conflicts — including those laid out by critics — by creating a massive "binder" that would outline all of the logistics of the arrangement, such as what areas of the house she would be able to access and when, a clause for "personal private time," and plans for household necessities such as groceries and laundry.

And while Mathis said she didn't take TikTok comments to heart — good or bad — she said there were people in her own life, particularly single friends who hadn't experienced divorce, who had expressed skepticism at her decision. "Why in the hell would you do that?" she said she's been asked.

"There's a lot of negativity," Mathis said, "but ultimately, parents know what's best for their kids."