The couple recently threw a lavish engagement party to celebrate their love. It included their closest friends, family and the Flipping 101 star's two children; Taylor, 10, and Brayden, 5, whom he shares with his ex-wife, Christina Haack.
"Oh my gosh, I lost my voice, he lost his. It was the most special night," Young tells ET's Nischelle Turner as the two co-hosted Entertainment Tonight on Wednesday. "It went so smooth and I said, this is a preview to the wedding day and it was the best day ever."
The two shared stunning photos and video from their party, including a clip of El Moussa dancing with his little girl.
"My daughter is my everything," he says. "I wouldn't have gotten through my divorce without her."
The pair got engaged last July after a year of dating. With the two having their own reality shows -- El Moussa has Flipping 101 and Flip or Flop, while Young stars on Selling Sunset -- where will fans get to see their nuptials?
"We don't know! We're filming the wedding, it would be Flipping 101 or my show," Young shares, adding that she is more than ready for her special day.
"I already have my wedding dress picked. I picked it, like, right away," the bride-to-be shares, teasing, "It's sexy, classy and something no one expects it to be."
In the meantime, fans can follow El Moussa and his ex-wife on their HGTV show. Season 9 is currently airing on Thursday nights. As for how his and Haack's relationship has evolved since announcing their split in 2017, the two couldn't be better.
"[Our relationship] is in a completely different place," El Moussa says. "She and I are getting along, we're co-parenting, getting along together, and I really think the episodes are getting better and better."
For Young, she says, "It was never an issue" having her fiancé work with his ex-wife. "Because it's work. It's his job," she explains. "They've been filming for 10 years, who am I to dictate? I am very supportive. We support each other through everything."
"No, no exes at the wedding," he stated, explaining that they are planning on having a small wedding. "Small, less distractions, more intimate, better conversations with the people around us. You know, we just think smaller is better."
"Just intimate, with our best friends and family," Young added. "We're gonna have to be strict with our list."