5 Seconds of Summer's Luke Hemmings Hints He's Married to Sierra Deaton in New TikTok

Bennett Raglin/Getty Luke Hemmings and Sierra Deaton

Has another 5SOS bandmate said "I do?"

On Monday, 5 Seconds of Summer musician Luke Hemmings shared a TikTok that left fans buzzing with questions as to whether he's already tied the knot with fiancée Sierra Deaton.

In the TikTok, Hemmings, 25, is seen playing the guitar and singing along to a track by Deaton, 31, titled "Little Do You Know."

As he sings the track, a voiceover says, "When you marry the girl that wrote this banger."

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A rep for Hemmings did not immediately respond to PEOPLE's request for comment.

The video quickly went viral — and the 5SOS fandom did not hold back on their reactions. On Twitter, one fan wrote, "luke hemmings sitting at home next to his wife and dog watching his stans freaking out be like," alongside a meme of a little girl watching a house burn down, with Hemmings' face photoshopped in place.

Though the couple got engaged in February 2021, they didn't reveal the news until June when they shared photos from the special moment on Instagram. Hemmings popped the question in an intimate setting in Malibu, California, a source told PEOPLE at the time.

"With shaking hands but a full heart I proposed to my best friend earlier this year," he wrote. "I love you Thao and I can't imagine my life without you ❤️ @sierradeaton."

Deaton — who Hemmings started dating in February 2018 — shared a sweet message of her own with a carousel of photos.

"It was fun keeping this a secret for so long, but my heart is nearly bursting at the seams. can't wait for forever 🤍 @lukehemmings," she wrote.

Deaton is a musician herself and competed on the third and final season of X-Factor US when she was in the duo Alex & Sierra alongside ex-boyfriend Alex Kinsey. Deaton later released music under stage name Essy and has provided background vocals for the band.

RELATED: 5 Seconds of Summer Is Here to Stay as They Celebrate 10 Years: 'It's Kind of Like a Marriage, Isn't It?'

The news of a potential marriage between the two musicians comes after 5SOS' other member Michael Clifford revealed to PEOPLE last month that he and his longtime girlfriend Crystal Leigh tied the knot in January 2021 — which also came as a surprise to fans.

Meanwhile, Clifford, 26, and Hemmings also caught up with PEOPLE in December about the release of their single "2011" which honored their 10-year anniversary as a group.

"We did this together. We never forget that. It's bonded us on a level that's unexplainable," Clifford told PEOPLE at the time. "It's really an unbreakable bond."

"We came together in such an organic way," added Hemmings. "We felt we had something special even when we were starting in the outskirts of Western Sydney. It's just honestly the friendship [that's kept us together.]"