Megan Fox turned 36 on Sunday night, and the actor celebrated her birthday with fiancé Machine Gun Kelly at a star-studded bash in Tao, Las Vegas.

The actor, who got engaged to the rapper in January, marked the occasion in a glittering jewel-toned strapless dress that she accessorised with a silver tiara.

When it came to her beauty choices, she opted for a slick, straight hairdo with a fringe, winged eyeliner and nude lipstick.

megan fox celebrates 36th birthday machine gun kelly
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Fox was joined by A-list celebrities, including 52-year-old rapper Diddy, who hosted the Billboard Music Awards the following day - on her actual birthday.

According to the Daily Mail, other stars who attended the bash included Mary J Blige, Usher, Heidi Klum, Lil Kim, Jermaine Dupri, Teyana Taylor, French Montana, Shensea, Ray J, Bryson Tiller and more.

megan fox celebrates 36th birthday machine gun kelly
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Ahead of her birthday, Fox told Entertainment Tonight's Denny Directo about her one request for the occasion.

'My main request is always just no cell phones,' she said.

'So, whatever we do, wherever we go, I just want there to be no phones.'

While on the red carpet at the Billboard Music Awards, the engaged couple discussed Fox's birthday plans, with Kelly saying: 'It’s my fiancée's birthday at midnight so we are celebrating her wonderful night.'

Fox responded: 'I’m boring I don’t drink, but I’m sure he’ll go off for me,' suggesting he would be doing most of the partying.

megan fox celebrates 36th birthday machine gun kelly
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But it was Kelly's reference to his and Fox's 'unborn child' at the awards that really caused a stir.

During the ceremony, the 32-year-old dedicated his 2022 song 'Twin Flame', from album Mainstream Sellout, to the Jennifer's Body star.

Before performing at the MGM Grand Garden Arena, Kelly said: 'I wrote this song for my wife.'

He then added: 'And this is for our unborn child,' after beginning his song.

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Following this, speculation rose as to whether Fox is pregnant, with one person tweeting: 'So did MGK just confirm that Megan Fox is pregnant with his baby?? [sic].'

Another wrote: 'Megan fox preggers???? Did mgk just say our unborn child!!!!! Wait!!!! [sic].'

Echoing these remarks, one shocked fan remarked: 'Megan Fox is pregnant?! What an announcement that was!! [sic].'

Fox shares three children - Noah, nine, Bodhi Ransom, eight and Journey, five - with ex-husband Brian Austin Green.

Kelly, meanwhile, has a 12-year-old daughter named Cassie, whom he shares with his ex Emma Cannon.

While the couple are yet to address the pregnancy rumours, prior to performing at the awards ceremony, Kelly told Entertainment Tonight about the special meaning behind the track.

'I wrote this song two years ago exactly today, played it for her. It's just all the trip. It's all meant to be,' he said.

Kelly added that the timing of his weekend his performance was ideal, saying: 'It's really cool because it's a Lunar eclipse tonight. It's a full moon. It's [Fox's] birthday tomorrow.'

Fox, too, spoke about the song, admitting she'd probably get emotional hearing the song as it has a 'really special secret meaning'.

She later quipped: 'But I can't cry and f**k up this eyeliner.'

Kelly, who proposed to Fox in January, understood to have taken place at Spa Botánico at the Ritz-Carlton Dorado Beach during the couple's stay in Puerto Rico, did so with a sentimental ring.

The standout design, which he worked on with Sophia Webster, features a pear-cut diamond that nods to his birth stone and an emerald - Fox's birth stone.

Webster told People amid their engagement: 'We were approached by Colson [Baker] to create a very special ring that had true connections to both Megan and himself.

'During the creative process, Colson had mentioned that Megan's both stone is emerald which he wanted to incorporate in some way along with a diamond, his birthstone.'

The designer revealed the diamond is a D-colour antique cut and the emerald is an untreated Columbian gem.

She also referred to the detail of the ring as 'both modern and quite extraordinary'.

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Sakaynah Hunter
Former News Editor

Sakaynah Hunter was the former Digital News Editor at ELLE.