United Kingdom, May 10 -- Heather Rae El Moussa's friendship with her husband's ex-wife is "developing".

The 37-year-old reality star is married to Tarek El Moussa and has two-year-old son Tristan with him but is also stepmother to Taylor, 14, as well as nine-year-old Braydon - whom he shares with Christina Haack.

And, she explained that working with Christina on 'The Flip Off' has led to them bonding.

She told Us Weekly: "I think friendship is a very special thing, like being a friend. And I think we're getting there, right? We're opening up to each other about things. We help each other through things. We talk about personal things with each other and guide each other through things. So our friendship is developing even more and more...