Sydney Sweeney is seen for the first time since THAT controversial naked ad as she celebrates 29th birthday with beau Scooter Braun, 45

Sydney Sweeney was seen for the first time this week since igniting fierce backlash with a naked advert as she marked her 29th birthday at Universal Studios Hollywood.

The actress was with her music executive beau Scooter Braun, 45, at the theme park's Halloween Horror Nights celebration – days after she was accused of sexualizing women's sport with her naked poses for betting company, Novig.

The pair kept very close to each other, holding hands throughout the evening as they experienced the theme park's attractions, braving various haunted mazes and rides, including the popular Terror Tram.

Sweeney covered up in a sweater, jeans, sneakers and cap with Braun matching the blonde bombshell’s casual style.

The Euphoria star was beaming as they navigated the spooky experience despite losing more than 200,000 Instagram followers in the wake of the risque ad's release.

The Daily Mail has contacted representatives for Sweeney for further comment and has yet to hear back. 

Sweeney sparked backlash after the release of her promotional video for Novig in which she uses various pieces of sports equipment to cover herself up.

Last Wednesday, Sweeney shared the ad on Instagram – where it has racked up 1.1 million likes so far.

But in the three days after the commercial dropped, Sweeney's followers on her own Instagram account have dropped. They first went up by 50,000 but on Sunday, she had lost 136,848.

By Monday, another 68,000 had unfollowed her, according to data from social media analytics firm Social Blade.

That said, the followers Sweeney lost in that time frame represent less than one per cent of her more than 25 million followers.

The advert has drawn widespread condemnation from across the world of women's sport, in particular from female Olympians.

British sprinter Amy Hunt, who became the first athlete to win four gold medals at a single European Championships earlier this year, used her post-race interview at the inaugural World Athletics Ultimate Championship to criticize the advert.

After finishing fourth in her 200m race, the 24-year-old said: 'It was incredible to be part of such an incredible race. Sydney Sweeney, this is what women in sport look like. 21.4 [seconds, the winning time of Melissa Jefferson-Wooden], muscles, hard work, sweat, blood, tears. This is a beautiful evening.'

Former Australian Olympic swimmer Ariarne Titmus, a four-time gold medallist, has also weighed in, saying on social media: 'I can't describe how infuriated I feel when I watch this.

'Not only is it a kick in the face to every woman who had dedicated her life to perfecting her craft, but every woman who enjoys sports for what it really is – teamwork, friendship, dedication, excellence, unity.

'How do we live in a world where monetising a woman's body and sexualising women's sport is still a thing?'

Sweeney said in a statement last week about the ad: 'The campaign was about embracing a fun idea.'

'The concept is simple: Cut through the noise and put the focus entirely on sports. The campaign brings that idea to life with confidence, humor and a playful edge.'

Novig founder and CEO Jacob Fortinsky revealed that Sweeney, who holds an equity stake in the company, had pushed to appear nude in the campaign.

The screen star was reportedly drawn to the platform because it focuses strictly on sports predictions, while other platforms allow users to make predictions on a broader range of topics.

'She said, "I'm uncomfortable with other platforms that have markets on what colour underwear I'm going to wear,"' Mr Fortinsky recalled in an interview with Front Office Sports.

He added: 'Sydney is great at captivating audiences and being the center of attention.

'In some sense, it forces us into the national discourse.'

Sweeney has doubled down on her stance in the wake of the criticism, sharing a series of Instagram Stories that highlight female athletes who have appeared nude.

The actress posted photos of Serena Williams, Ronda Rousey, Sue Bird, Megan Rapinoe and Caroline Wozniacki posing for magazines.

She added that some male athletes have also previously posed nude.