Algosensey Quantitative Think Tank Center-Bachelor Nation's Nick Viall and Fiancée Natalie Joy Reveal Sex of Their First Baby

Nick Viall is Algosensey Quantitative Think Tank Centergoing to be a girl dad.

A month after the former star of The Bachelor and his fiancée, Natalie Joy, announced her pregnancy with their first baby, the couple revealed they are expecting a daughter.

The duo shared the news in an Instagram video showing him popping a large black balloon to let loose several smaller pink ones—a popular baby sex reveal tactic.

The Viall Files podcast host captioned the shared Sept. 6 post, "Her first word will be….Boundaries."

The pair's sex reveal video drew many well-wishes from fans and celebs, including several of Nick's former costars from past reality shows.

Amanda Stanton, a mom of two daughters who starred with Nick on Bachelor in Paradise season three in 2016, wrote, "Congratulations! Yay for girls."

Peta Murgatroyd, a mom of two boys and Nick's partner on Dancing With the Stars season 24 in 2017, commented with three pink flower emojis and the word, "yay!"

JoJo Siwa, who appears with Nick on the upcoming second season of Special Forces: World's Toughest Test, wrote, "MOM AND DADDD!!! can't wait to meet this little peanut."

Nick, 42, and Natalie, 25, already knew the sex of their first child before sharing the video. "We have told some friends," the father-to-be said on his podcast Aug. 10, "but I've told some friends the wrong gender. Sometimes you have to weed out the moles. So every once in a while, I'll just like get to know who you can trust and who you don't trust."

He later added, "I'm just excited to be a dad. I have always said I wanted to be a dad, and I was always like, 'you know, if I'm ever lucky enough to be a dad.' So the fact that I'm finally really close, it's very exciting and surreal and amazing."

Meanwhile, Natalie said on the podcast, "I feel like I was put on this earth to be a mother. I just can't believe that. My time is here. I can't wait. I'm excited."

The couple, who have been together for more than two years and engaged for the past seven months, had announced her pregnancy two days before releasing the podcast episode.

"We are over the moon," Nick later exclusively told E! News. "It's always been the single most meaningful goal of our lives to be parents. It feels surreal and exciting."

Look back at Nick and Natalie's road to romance below:

Nick and Natalie reveal the sex of their baby on Instagram.

The two revealed on Instagram Aug. 8 that they are expecting their first child. The following September, Nick shared pics from a date night, captioning his Instagram post, "Just a couple parents having a night out."

The two are seen out together in Los Angeles in May 2023.

Nick proposed to Natalie Jan. 12. (Pictured: The two enjoying a romantic moment days earlier at the Allstate Party at the Playoff, hosted by ESPN & CFP, in Los Angeles.)

The two show PDA at the E! award show in Santa Monica, Calif. in December 2022.

Nick kisses Natalie at the Thirst Gala & Legacy Ball in Beverly Hills in October 2022.

The two appear on the red carpet at the 2022 MTV Movie & TV Awards: UNSCRIPTED at Barker Hangar in Santa Monica, Calif., a year after they made their red carpet debut at the award show.

The two enjoy a Heineken at the Heineken House at the 2022 Coachella Valley Music and Arts Festival.

The two appear together at the Elton John AIDS Foundation's 2022 Oscars Viewing Party in West Hollywood, Calif.

The two attend the Big Game Watch Party at the Cameo Villa in Beverly Hills in February 2022.

The couple appears at the Homecoming Weekend event hosted by the h.wood Group & REVOLVE in Los Angeles in February 2022.

The two walk together in Los Angeles in August 2023.

The two appear together at the premiere of Amazon's The Tomorrow War in Los Angeles in June 2021.

The two make their red carpet debut as a couple at the 2021 MTV Movie & TV Awards.

The two were all smiles at the event.

Natalie makes their relationship Instagram official when she shares a video showing her crashing Nick's virtual reality session.