The "Flip or Flop" star, 39, reportedly "blew up" at his co-host and ex with whom he shares two children. According to TMZ, El Moussa allegedly went nuclear on Haack, 38, after he took umbrage with the manner in which Haack signaled that she and the crew were ready to begin filming.
The gossip outlet, citing production sources, alleged El Moussa compared the mother of his children to his fiancée, Heather Rae Young, spewing that Young, 33, is better looking and has more money than Haack.
The site further reported that El Moussa allegedly boasted that he "made" Haack and even called her a "washed up loser" while basking in the fact he takes satisfaction in seeing her fail.
During his alleged diatribe, El Moussa is also said to have shouted "Look at me, look at me, look at me. It’s called winning" and ended his display, allegedly adding, "The world knows you're crazy!"
El Moussa reportedly became angry at Haack after her recent admission that she smoked toad venom before she met her current boyfriend amid her spiritual enlightenment. Additionally, TMZ sources relayed that El Moussa’s main concern is that of their two children.
Reps for El Moussa, Haack and HGTV did not respond to Fox News’ requests for comment.
Hours after the news broke, El Moussa and Young hopped on a private plane in New York to the frequent celebrity hangout destination of St. Barths.
Young, a reality realtor and star of the Netflix series "Selling Sunset," shared photos to her Instagram Story on Tuesday of the pair en route as well as enjoying breakfast on the beaches of paradise.
"Loooonnngggg day off travel to get to our much needed vacay," Young captioned the Story post, tagging El Moussa’s Instagram account. "Rest, and relaxing time."
"Breakfast with my sweet love," Young added in another post of a grizzly-bearded El Moussa donning a black cut-off shirt, shades and a black hat.
Meanwhile, this reportedly wasn’t the first instance in which El Moussa allegedly berated Haack while the former couple – who were married from 2009 to 2018 – filmed their collaborative real estate reality show. The exes are also co-executive producers on the long-running series.
In June, Haack’s divorce from Ant Anstead was finalized.
It was revealed at the time that the exes will be sharing legal and physical custody of their 1-year-old son Hudson.
Anstead, 42, and Haack began dating in 2017 and married in December 2018 in a ceremony in Newport Beach. The "Christina on the Coast" star split from her first husband, El Moussa, in May 2016. Their divorce was finalized two years later. The exes share two children: daughter, Taylor, 10, and son, Brayden, 5.
In recent weeks, photos have shown that Anstead and Haack have moved on and have already settled into new relationships. Anstead has been seen out and about holding hands with Oscar-winning actress Renée Zellweger.
Meanwhile, Haack recently confirmed she is dating Josh Hall, who is a realtor.
Fox News’ Melissa Roberto contributed to this report.