Luke Hemmings and Sierra Deaton's Relationship Timeline

Luke Hemmings, Sierra Deaton — Photo: Stefanie Keenan/Getty

Luke Hemmings and Sierra Deaton are in perfect harmony.

The 5 Seconds of Summer singer and Deaton first went public with their relationship in 2018 and have marked many relationship milestones since then.

In June 2021, the couple announced their engagement with a series of photos of the proposal on Instagram. "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." A source revealed to PEOPLE that Hemmings popped the question in an intimate setting in Malibu, California, back in February 2021.

After sparking marriage rumors in early 2022, Hemmings confirmed he and Deaton were husband and wife during a Golden Globes afterparty.

In addition to walking various red carpets together, the two have given many glimpses of their love story on social media, posting sweet tributes to each other. They have even collaborated on music together as Deaton was featured on 5 Seconds of Summer's hit single "Older."

Here's a complete timeline of their relationship.

01 of 13

July 2018: Luke Hemmings and Sierra Deaton go Instagram official

Hemmings and Deaton started dating in 2018. The pair officially went public with their romance that July when the former X Factor winner shared a cute snap of a smooch with the 5 Seconds of Summer singer on Instagram.

02 of 13

August 19, 2018: Luke Hemmings and Sierra Deaton hug in an Instagram snap

In August 2018, Hemmings shared his own PDA photo of the two hugging backstage at a 5SOS concert. He simply captioned the photo: "thao."

03 of 13

December 6, 2018: Luke Hemmings and Sierra Deaton make their red carpet debut as a couple

The couple made another relationship milestone when they made their red carpet debut as a couple at the GQ Men of the Year Party in December 2018. The pair posed for photos, hand in hand.

04 of 13

February 11, 2019: Luke Hemmings celebrates Sierra Deaton's birthday

For Deaton's birthday on Feb. 11, 2019, Hemmings shared a heartfelt post, writing, "Happy birthday my love ! ^.^ You make me the happiest ever and I'm so thankful to have you in my life! Hope you stick around as long as you can tolerate how annoying I am, I love you Thao."

05 of 13

July 16, 2019: Sierra Deaton celebrates Luke Hemmings' birthday

Five months later, Deaton returned the favor with her own loving tribute on Hemmings' July 16 birthday. Alongside a gallery of cuddly images of the pair, Deaton wrote, "there aren't enough words to articulate how much i love every ounce of the being you are. lu, thank you for being my rock through hell or high water, but mostly for telling me everything i cook is the greatest thing you've ever tasted lmao. happy birthday to my very best friend. my soul mate. i love you forever."

06 of 13

September 9, 2019: Luke Hemmings and Sierra Deaton attend a DKNY event

In September 2019, the pair coordinated in dark suits as they attended an event celebrating the 30th anniversary of DKNY in New York City. The couple held hands while posing for photos.

07 of 13

September 10, 2019: Luke Hemmings and Sierra Deaton attend New York Fashion Week

During NYFW, the duo made a handful of appearances together in the Big Apple, including a show for Christian Cowan in September 2019. Hemmings and Deaton were also spotted sitting front row at the event.

08 of 13

September 10, 2019: Luke Hemmings and Sierra Deaton step out in N.Y.C.

Hemmings and Deaton smiled for the cameras as they made their way into the Oscar de la Renta show at NYFW in September 2019. Again, the fashionable duo coordinated their outfits.

09 of 13

January 14, 2020: Luke Hemmings and Sierra Deaton take a trip to Vietnam

In January 2020, Hemmings took a trip to Vietnam with Deaton, who is of Vietnamese descent. The two commemorated their excursion by taking a photo at Ha Long Bay, which Hemmings playfully captioned, "Ha Long Bae."

10 of 13

June 8, 2021: Luke Hemmings and Sierra Deaton announce their engagement

A source revealed to PEOPLE that Hemmings popped the question in an intimate setting in Malibu, California, back in February 2021.

11 of 13

February 21, 2022: Luke Hemmings and Sierra Deaton spark marriage rumors

Luke Hemmings and Sierra update — Luke Hemmings/Instagram

In February 2022, the duo sparked marriage rumors after the 5 Seconds of Summer singer referred to being married to Deaton in a TikTok video.

The following month, Hemmings suggested they weren't actually married in an interview with Extra and that he was implying Deaton was the woman he was going to marry.

12 of 13

September 7, 2022: Sierra Deaton appears in 5 Seconds of Summer's "Older" music video

Ahead of the group releasing their fifth album, 5SOS5, on Sept. 23, 5 Seconds of Summer released the single "Older" featuring Deaton on background vocals. Deaton also co-wrote the song. Deaton told Rolling Stone that the ballad was "one of the most special records" he's been involved in creating.

13 of 13

January 7, 2024: Luke Hemmings confirms he's married to Sierra Deaton

During an interview with Entertainment Tonight at the Billboard's 2024 Golden Globes afterparty, Hemmings confirmed his marriage to Deaton.

When speaking about his eye makeup, he said, “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.”

Then, when asked how married life was treating him, Hemmings replied that things were “good.” He added, “It’s very good. I love it. She’s here tonight, she’s somewhere in there.”