5SOS: Luke Hemmings reveals his girlfriend Sierra Deaton is bisexual

5 Seconds of Summer star Luke Hemmings reveals his longtime girlfriend Sierra Deaton is bisexual as they celebrate Pride Month together

He’s usually quiet when it comes to his personal life.

But on Monday, 5 Seconds of Summer’s Luke Hemmings surprised his 6.4 million Instagram followers by revealing that his girlfriend, Sierra Deaton, is bisexual.

The couple looked thoroughly loved-up as they celebrated Pride Month together in Los Angeles.

Who knew? Australian singer Luke Hemmings (left) has revealed his long-time girlfriend Sierra Deaton (right) is bisexual as stepped out to celebrate Pride month together in LA on Monday

The Youngblood hitmaker, 23, wrote: ‘There is still so much work to be done but wanted to wish everyone a happy pride.’

‘Especially to my beautiful bisexual biracial angel,’ he added, tagging the 29-year-old singer-songwriter. 

Sierra also appeared to have a rainbow tattoo on her left arm, but it’s unclear if it was permanent or temporary. 

Proud: There is still so much work to be done but wanted to wish everyone a happy pride' 'Especially to my beautiful bisexual biracial angel,' before he tagged his doting love

Proud: There is still so much work to be done but wanted to wish everyone a happy pride’ ‘Especially to my beautiful bisexual biracial angel,’ before he tagged his doting love

The couple have been using their platforms on Instagram to advocate for the Black Lives Matter movement  in recent days.

They have been regularly sharing sharing links to protests and donation websites.

Sierra rose to fame after winning the U.S. version of The X Factor in 2013.  

LA based: Luke, 23, who grew up in Sydney's Western Suburbs has relocated to LA with his fellow 5 Seconds of Summer bandmates

LA based: Luke, 23, who grew up in Sydney’s Western Suburbs has relocated to LA with his fellow 5 Seconds of Summer bandmates

The lovebirds have been dating since February 2018. 

It comes after Sierra wrote a touching tribute to her rocker boyfriend’s on his 23rd birthday.

‘How the universe bundled up the most kind, hardworking, funny, talented, and sexy man into one human is beyond me,’ she wrote.

‘Luke, 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.’

Happy in love: The couple have been dating since February 2018. Sierra recently gushed over her beau online, describing him as hardworking and funny

Happy in love: The couple have been dating since February 2018. Sierra recently gushed over her beau online, describing him as hardworking and funny