Heather Rae El Moussa is flipping out over her love for Christina Haack.

The Selling Sunset alum shared a sweet birthday tribute to her husband Tarek El Moussa’s ex-wife, proving that their friendship is structurally sound.

“Happy birthday @christinahaack !” Heather posted to Instagram July 9. “Some of the iconic moments we’ve shared these last few years.”

And the 38-year-old was especially grateful that she and Christina have been able to build such a beautiful family with Christina and Tarek’s kids Taylor, 15, and Brayden, 10; Heather and Tarek’s son Tristan, 2; and Christina and ex Ant Anstead’s son Hudson, 6.

“What a gift it is to watch our co-parenting turn into real friendship, cheering each other on in every chapter, every venture, every win!” Heather continued. “Cheers to many more celebrations.”

Alongside the sweet message, Heather shared several snaps of herself and the Flip or Flop star including one of them posing in a pool wearing matching hot pink bikinis. In another, Christina can be seen pouring Heather a glass of her ClĂ© CachĂ©e champagne, with the two sporting matching black and white bikinis in a photo while also applying some of Heather’s HRE lipgloss.

Christina was especially touched by the celebratory message, commenting, “Awww love you, our friendship, co-parenting together and working together.”

The 42-year-old added, “Cheers to another year of bigger and better things to come.”

Throughout Heather and Tarek’s romance, the couple—who married in 2021 following his 2018 divorce from Christina—have been candid about how they made it a priority to have a great relationship with the Christina on the Coast alum, which Christina has truly appreciated.

“We’ve had our ups and downs, but mostly we've been great co-parents throughout everything," Christina shared with E! News in 2025. “All three of us love these kids like more than anything, so we've always made them a priority."

And that was a sentiment that Heather echoed, telling E! later that year, "We're actually friends, we co-parent together, we're raising kids together. We've turned negatives into positives." 

For a deep dive into Heather and Christina’s family tree, keep reading.

Christina and Tarek welcomed their first child together on Sept. 22, 2010.

Following their divorce, the pair continued to co-parent their daughter, who Christina has described as an "old soul who one minute can talk super deep about life and then quickly go back to being a kid."

"Her greatest ability is being able to start a conversation with anyone, anywhere," she said of Taylor. "Fun, smart, athletic, HAPPY, and always keeping us on our toes."

Christina and Tarek welcomed their second child together on Aug. 20, 2015.

In addition to their oldest child Taylor, the two have continued to co-parent Brayden after their divorce. In the past, Tarek has described their son as "a ball of energy" and the "sweetest boy with the biggest heart."

"No words can describe how much brighter this boy makes my day," Tarek shared. "I feel blessed every single day to be his and Tay's dad and raising him and seeing him grow up makes me the happiest dad alive."

Almost a year after announcing her split from Tarek, Christina started dating Ant, a TV presenter from England, in October 2017. The two went public with their relationship in January 2018—the same month Christina's divorce from Tarek was finalized—and tied the knot in a winter-themed wedding at their home in Newport Beach, Calif., on Dec. 22, 2018.

Christina and Ant—who is dad to daughter Amelie and son Archie with his first wife Louise Storey—welcomed their first child together, son Hudson, in 2019.

The couple were married for less than two years before announcing their separation in September 2020. Their divorce was finalized nine months later.

Since the split, Ant has moved on with actress Renée Zellweger.

Christina and Ant welcomed their son on Sept. 6, 2019. At the time, the baby boy arrived weighing 7 pounds, 7 ounces and measured at 19.5 inches long.

Though they agreed on shared legal and physical custody of Hudson when their divorce was finalized in June 2021, Ant filed for full custody in April 2022, claiming in court documents that his ex spends roughly "9 full days" with their child each month.

The following December, the exes reached an agreement in which both would "continue to have joint legal and joint physical custody" of Hudson, according to court documents obtained by E! News.  

Tarek met the Selling Sunset star on the Fourth of July in 2019, when they were partying on boats that had docked next to each other at a marina in Newport Beach, Calif. Later that month, the pair were spotted kissing on a yacht and Tarek confirmed to E! News they were dating that August, saying, "I never thought I'd say this word again, but this beautiful young lady, Heather Rae, is my girlfriend, officially."

The couple got engaged in July 2020 and became husband and wife on Oct. 23, 2021, exchanging vows during a romantic outdoor ceremony near Santa Barbara, Calif.

Heather has often referred to herself as the "bonus mom" of Tarek's two older children, Taylor and Brayden. "I already feel like I have two kids," she previously explained to E! News. "I'm raising Tarek's babies, and we have them 50 percent of the time. I am such a good bonus mommy. I adore those kids. I raise them like they're mine."

Tarek and Heather welcomed their son on Jan. 31, 2023. At the time, the baby boy arrived weighing 7 pounds, 7 ounces.

He was named Tristan because "Tarek was supposed to be named Tristan," according to Heather, "and his parents ended up naming him Tarek."

After calling it quits with her second husband Ant, Christina began dating Josh in 2021. The pair went public with their relationship that July, with Christina revealing that they had been together for "a few solid months."

According to the Flip or Flop star, she met Josh, a licensed realtor, that spring at a time in her life when she "wasn't in a state of fear or fight-or-flight" and had "taken time off social, hired a spiritual coach and smoked a Bufo toad" to "reset" her brain. 

Christina and Josh got engaged that September and tied the knot on Oct. 6, 2021.

Their actual wedding date wasn't known until Josh filed for divorce on July 15, 2024, citing irreconcilable differences as the reason for the split.

Until the process of remodeling her childhood home unfolded on the July 11, 2024, episode of Christina on the Coast, she had kept her roots pretty private, mainly sharing glimpses of her parents as grandparents.

In 2019, she shared in an Instagram post that "we all sit together—my family and Tarek's family" when they watch Taylor perform at her school's annual Christmas concert.

"A couple people acknowledged how nice this is- I know there are a lot of divorced couples (including Tarek's mom and dad) who do this too and it's honestly easier for everyone," she wrote at the time. "Plus Taylor's face lights up when she sees us all in the same row supporting her."

The older sister of Tarek, Angelique is the owner of Latitude 33 Hair Artistry in Anaheim, Calif. She purchased one of Tarek and Christina's flipped homes on an episode of Flip or Flop in 2014 and later filmed a digital series with her HGTV host bro in 2019.

Tarek's mother Dominique is no longer with the Flipping 101 star's father, whose name he has never publicly shared. She is currently married to Robert, who describes the El Moussa matriarch as "the love of my life" on Instagram.

Tarek has never shared his father's name, though in a November 2017 Facebook post he announced that his "old man" had turned 70 years old.

"The relationship between a father and his children is so important. I was lucky enough to have a supportive and motivating father that made me believe I could accomplish anything in the world," he captioned a picture of the family's birthday celebrations for the patriarch. "I can say that I wouldn't be where I am today without the support of my dad. I will take all the lessons I've learned from him and pass it on to my children."

In an interview with Country Living, Tarek said his father was "raised Catholic in the Middle East in Lebanon and then Egypt" and met his mother, who is from Belgium, in Europe as a teen.