Jax Taylor and Brittany Cartwright are putting on a united front ahead of their son Cruz's latest milestone.

Despite The Valley stars' recent separation, the estranged couple are reuniting this weekend to throw an adorable "Three Rex"-themed birthday party for Cruz, who turns 3 on April 12.

"Cruz loves dinosaurs," Brittany exclusively told E! News, "so we naturally had to choose this theme."

The celebration, which is being planned by Picnic + Petal with decorations by Glitz and Gather, will take place at an L.A.-area Skyzone trampoline park. Fellow Bravo stars expected to be in attendance are Vanderpump Rules' Scheana Shay and her daughter Summer, Lala Kent and her daughter Ocean and Tom Schwartz.

The celebrity guest list also includes Jax and Brittany's The Valley castmates Janet and Jason Caperna, Zack Wickham, Kristen Doute, Luke Broderick, Michelle Lally and Danny and Nia Booko. 

And judging by a mood board shared with E!, guests can expect dinosaur balloons, jungle decor and a prehistoric-designed cake and treats.

Cruz's third birthday celebration comes nearly two months after Brittany announced that she and Jax had separated after four years of marriage and are now living apart.

But their marriage troubles aside, Jax made it clear they continue to put Cruz's best interests first.

"I gotta do what's best for my son," the 44-year-old exclusively told E! last month. "He's number one and we both agree on that. It's about knowing he's got two loving parents that love him to death and he's gonna have the best life possible, whether we are together or not."

And Brittany agrees.

"Jax is a great father, I'll give him that," the 35-year-old shared on Watch What Happens Live April 2. "That's our main priority, no matter what."

See Jax and Brittany's relationship unraveling play out when The Valley airs Tuesdays at 9 p.m. on Bravo. And keep reading for a full timeline of their split.

Years before they even got married, Jax Taylor cheated on Brittany Cartwright in 2017 when he hooked up with former SUR waitress Faith Stowers. 

"This isn't my first time being caught cheating," Jax admitted at the time as the drama played out on Vanderpump Rules. "In the past, I've gone through months and months of deny, deny, deny, and that didn't work for me." 

But while a devasted Brittany broke up with him, they got back together months later and eventually wed in 2020.

Fast forward to February 2024, Brittany announced she and Jax—who share 2-year-old son Cruz—had separated after four years of marriage. 

"Yes, marriages in general are very hard and I've had a particularly rough year this past year," the Kentucky native shared on their When Reality Hits podcast. "Jax and I are taking time apart and I made the decision to move into another home to take some space for the sake of my mental health."

"I'm taking one day at a time," Brittany added. "I don't know what the future holds, but right now my focus is on being the best mom to Cruz."

One month later, the cracks in the couple's relationship became much more apparent when Bravo released the trailer for its new series The Valley.

"I don't feel like he's attracted to me, we don't have sex ever," Brittany admitted in the March 11 preview before Jax added, "It's so hard to be married sometimes."

Plus, costar Janet Caperna teased in the clip, "There's a rumor about Jax cheating online."

However, Jax slammed allegations of infidelity days after the trailer release.

"We're just having a little communication issues right now. That's all, there's nothing else," he exclusively told E! News March 14 at The Valley premiere party. "There's no cheating. There's no infidelity anywhere. It's just communication. I know it's shocking, but people sometimes just don't get along and that's life."

"We see each other every single day," he added. "The only thing that's different is we just don't sleep under the same roof. That's it."

Despite rumors, Brittany confirmed Jax cheating did not cause their breakup and shared the true timeline of their separation.

"We got into a very bad fight and I decided to pack up my stuff," the 35-year-old exclusively told E! News March 18, "and I've been staying in an Airbnb since January 24."

"I'm doing it for my mental space," she added, "and I feel very strong with my decision to get out for a while."

Despite their personal drama, the estranged couple agreed on one thing: They are doing what's best for 2-year-old son.

"He's no. 1 and we both agree on that," Jax told E!. "It's about knowing he's got two loving parents that love him to death and he's gonna have the best life possible, whether we are together or not."

As for their increased fighting, Brittany agreed, "I just don't want that for our son. I don't want him growing up thinking it's normal to live like that."

Brittany admitted in March that "there's always hope," but she just needs Jax to put in the work.

"I don't think anybody will ever love Jax the way I've loved Jax," Brittany told E!. "Over all these years, I've been through so much with him and I'm stuck by his side through everything. So I think that if he makes certain changes that I've asked, maybe we could get back together. But right now, I just really need to figure out myself. I felt really strong and really proud of myself for being able to step out and do what's right for me. My mental health is super important."

One person who wasn't so shocked by Jax and Brittany's separation? Their former SUR boss Lisa Vanderpump.

"Everybody predicted that when they got married," the Real Housewives alum shared with E!. "They said, 'Oh this won't last long,' but I kind of never liked to draw conclusions."

"I don't know what the reason was," she added, "but I imagine it was probably something to do with Jax's bad behavior. I'm not sure, but the indicator of future behavior is normally past behavior."

"I think it’s for the best," their longtime friend Scheana Shay told E! News March 23 of the split. "I think she deserves better and she deserves a partner who’s going to treat her with respect."

And the couple's The Valley costar Kristen Doute agreed with Scheana.

"I'm proud of Brittany for setting boundaries for making the choice for her," Kristen admitted. "But I'm very hopeful that they can work this out. But that's on Jax, that's not on her."

(E! and Bravo are both part of the NBCUniversal family)