Young took to Instagram on Sunday to share a heartfelt message alongside a slideshow post featuring photos of El Moussa's romantic seaside proposal.
"One year ago today I made the best decision of my life by saying yes to spending forever with the most special man," Young wrote in her swooning post.
Young continued, "I remember when he proposed… in that moment everything melted away and I was just staring at my forever person, fully in tears thinking how lucky I was that I got to spend the rest of my life with him. ♥️"
The Flip or Flop star popped the question on the sand at the Descanso Beach Club on Catalina Island on Saturday, July 25, 2020. El Moussa rocked a classic tux as he got down on one knee and slipped the ring on Young's finger, as she stunned in a shimmering, elegant black dress.
"Thank you to the man who has put a smile on my face every single day," Young wrote in her post. "You have shown me what true love and family are all about. I fall more and more in love with you as I watch how amazing of a dad you are with the babies, how hard you work, and how you put family and your loved ones first in your life."
El Moussa, 39, is the father of two children -- daughter Taylor, 10, and son Brayden, 5 -- whom he shares with ex Christina Haack.
"You’re my best friend, my person, and my rock," Young concluded her loving post. "Happy 1 year of being engaged baby! Cheers to a lifetime of You & Me ♥️"
Young told ET in May 2020 that she and El Moussa committed to each other after just two dates. She said she was happy to be a "bonus mom" to his kids, and has a great relationship with his ex.
"I've never been a mom. I'm new to all this," Young explained. "But as a woman, I just kind of felt like, 'What would I want being in her situation?' So it felt only right for me -- that I'm gonna be living with the children, being around the children all the time -- that I would reach out to her. And we have a great relationship. We talk about the children and it's great. It's been such an amazing experience for me being this new 'bonus mom.'"
In April, Young joined ET's Nischelle Turner as a guest co-host on Entertainment Tonight, and she opened up about how excited she is for their wedding.
"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."
With the two having their own reality shows -- El Moussa has Flipping 101 and Flip or Flop, while Young stars on Selling Sunset -- many fans are wondering where they will get to see the nuptials?
"We don't know!" Young shared. "We are filming the wedding, and it would be Flipping 101 or my show."
See more on El Moussa and Young in the video below.