Tarek El Moussa shares the big secret he asked his 9-year-old daughter to keep

Before Tarek El Moussa popped the question to now-fiancee Heather Rae Young, he confided in his 9-year-old daughter, Taylor.

“Taylor knew I was proposing before anybody else,” El Moussa, 38, revealed while speaking with People. “I was like, ‘Honey, I’ve got to tell you something. I really need you to be a big girl here.’ And she did it. She didn’t tell anyone.”

The “Flip or Flop” host surprised Young, 32, with an eight carat emerald-cut diamond ring while they were celebrating their one-year anniversary in Catalina Island, California, on Saturday. Taylor started checking in for updates as soon as they pulled out of the driveway for the romantic getaway.

“She texted me a million times that day saying, ‘Did you do it? Did you do it? Did you do it?’” El Moussa revealed.

Young, star of Netflix's "Selling Sunset," can't believe that Taylor didn't spill the beans.

"She didn't even lead on anything," Young marveled. "I had no clue! She’s such a great girl.”

El Moussa shares Taylor and son, Brayden, 4, with his ex-wife Christina Anstead. The couple separated in 2016 and divorced in 2018 after nine years of marriage.

Anstead has since remarried English TV presenter Ant Anstead, with whom she shares a son, Hudson, 10 months.

Prior to meeting Young, El Moussa was pressed by Taylor about when he would get a girlfriend.

“She was definitely ready for it. She loves Daddy and all, but I think she wanted a little more in the household,” he told TODAY Parents in Dec. 2019. El Moussa noted that Taylor and Young had an immediate bond.

"Taylor was comfortable with Heather Rae right away," he gushed.

So, it wasn't a surprise that Taylor couldn’t contain her excitement when El Moussa shared his proposal plans earlier this month.

“Oh my God, that’s the most excited I’ve ever seen her,” he raved to People. “She was thrilled. She just loves Heather, looks up to Heather, adores Heather, wants to be like Heather — it just makes me so happy.”