HGTV stars Tarek and Heather El Moussa, Christina Hall invoke Princess Diana: 'Three of us in this marriage'

Tarek and Heather El Moussa aren't letting the past negatively affect the future, especially when it comes to cultivating healthy relationships within their family.

The real estate experts put in some serious elbow grease toward their friendship with Christina Hall, Tarek's ex-wife, and created an alliance that not only benefited their personal household but also helped form a bond between the pair for their new HGTV series, "The Flip Off."

In an Instagram clip featuring the trio,...