Christina Haack, 42, proved once again that she is very close to Heather Rae El Moussa, 37.

On Wednesday the ladies posed side by side while on vacation in Las Vegas.

Both were in sexy little bikinis that showed off their very toned and tanned figures as they smiled for the cameras as if they were having the time of their life.

El Moussa's suit was light purple with a wrap mini skirt as she wore beige-and-gold shiny sunglasses with her hair up and Haack's suit was black with gold round accents as she added black sunglasses while wearing her hair down.

They each had a glass of champagne in their hands as they were celebrating Haack's birthday party. 

They looked more like sisters than pals. But they have an even more interesting background than that. 

Christina used to be married to Heather's husband Tarek El Moussa. They are so chummy that they are all working together on the reality TV show The Flip Off.

Also in the post, Heather posed with Tarek and Christina was seen with her new boyfriend Christopher Larocca. 

'What happens in Vegas…ends up on Instagram,' wrote Heather in her caption. 'Quick 24 hour trip to Vegas with the crew to celebrate Christina’s birthday!'

Haack and El Moussa rose to fame as the stars of the HGTV show Flip or Flop.

They were married from 2009 until 2018, when they went their separate ways, and share two children: Taylor, 14, and Brayden, 9.

El Moussa and Rae welcomed their son, Tristan, in January 2023.

Haack is also the mom of Hudson, 5, whom she shares with former husband Ant Anstead.

'It’s nice that you all get along! Not many can do this!' wrote one stunned fan. 

'I adore any couple who can make co parenting a beautiful journey. This is absolutely beautiful!! This makes it easy and safe for the kids❤️❤️❤️' said another. 

The trio has also worked together on their own home improvement show called The Flip Off.

Others were concerned that Haack might be jumping from the frying pan into the fire with a new relationship so soon after her contentious divorce from her third husband Josh Hall.

'Does she need another guy in her life so fast? Not a good example for her daughter!' asked a worried follower.

'She moves on quick!' commented another. 

The peaceful outing comes on the heels of El Moussa’s recent arrest in Las Vegas earlier this month, following an altercation at The Palazzo at the Venetian hotel.

According to reports, the incident began when a man allegedly bumped into El Moussa’s father and made a comment, prompting El Moussa to allegedly assault him.

The Real Estate Elevated co-founder could face charges in connection with the incident.