“Our best kept secret”: Luke Hemmings and Sierra Deaton announce the arrival of their baby girl

Luke Hemmings has entered a new chapter: fatherhood.

The 5 Seconds of Summer frontman revealed on Friday, August 22, that he and his wife Sierra Deaton recently became parents. The couple shared the update with a pair of intimate photos, one capturing their newborn daughter’s hands, and another of a then-pregnant Sierra Deaton smiling as Hemmings held her baby bump.

On Instagram, he wrote:

“Our best kept secret … Written and Produced by Sierra and Luke Hemmings."

In a follow-up comment, Luke Hemmings explained the couple’s decision to go public now after initially keeping the news private.

“In our perfect world, we’d keep our daughter a secret forever… for similar reasons we chose to never share our wedding photos from years ago. However, going into this next album cycle, I’m very aware that her existence would inevitably leak.”

The Youngblood hitmaker continued:

“To avoid any speculation, we’re posting this now and humbly asking for everyone to respect her privacy. If you see us in public, please avoid taking or sharing photos of her as we don’t plan on publicizing her name, birthdate, or face any time in the near future. Thank you for understanding and for the support. All our love, The Hemmings.”

Fans eagerly took to social media to celebrate Luke Hemmings and Sierra Deaton's recent milestone in their marriage.

"GIRL DAD 5SOS GIRL DAD 5SOS OH MY GODDDDDD IM SO HAPPY FOR THEMMM," a fan wrote on X (Twitter).

"Im so godd**n happy for them," one said.

"This definitely has a hippie aesthetic. Wonderful. I guess everyone lives their Summer of Love in their own way," another commented.

"MICHAEL AND LUKE ARE GIRL DADS IT MAKES SO MUCH SENSE," an online user replied.

"I KNEW IT!!!! CONGRATS TO THEM," one tweeted with crying emojis.

"so happy for them oh my god, are you kidding me?" another fan added.

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Luke Hemmings on marriage with Sierra Deaton: "It's very good"

The milestone comes years after Luke Hemmings proposed to Sierra Deaton in 2020, following their romance that began in 2018. At the time, he wrote:

“With shaking hands but a full heart I proposed to my best friend earlier this year. I love you Thao and I can’t imagine my life without you @sierradeaton.”

In 2024, the 5SOS member confirmed he and Deaton are married, sharing with Entertainment Tonight:

“It’s very good. I love it. She’s here tonight, she’s somewhere in there.”

At the time, the musician also talked about his eye makeup, revealing that it was his partner's doing.

“Thank you! My wife did it. Usually I do it for stage but she’s taught me well and she did it tonight. It’s a big event so she did it.”

Meanwhile, the band’s momentum continues. He rejoined Michael Clifford, Calum Hood, and Ashton Irwin in the studio late last year. Photos posted on 5SOS’ official account showed the group recording in Nashville.

Bassist Hood told Rolling Stone in June:

“There’s always conversations going. There’s always people dreaming up things. What if we do this, what if we do that? So fear not, because there’s always something going on.”