Her glamorous makeup look consisted of a bright red lipstick, several layers of mascara to bring attention to her beautiful brown eyes and blush on the apples of her cheeks.

The two-time Grammy winner wore her blonde hair in a sleek ponytail, reminiscent of her trademark half-up, half-down hairstyle that became just as famous as her when launching her music career in 2014.

The father-of-one, 31, and Grande arrived separately at the event and did not pose for photos together at the red carpet ahead of the show.

The Tony Award-winning musical is currently running at the St. James Theatre.

As she made her way to the theatre, Grande was mobbed by fans asking for pictures after she exited her car.

It was first reported back in July that Ariana and Ethan were dating, amid her divorce from Dalton Gomez, 28, and his from wife Lilly, 29. Ariana’s divorce was finalized on October 6.

Earlier this month, it was reported that Grande and Slater have taken their relationship to the next level, with the Dangerous Woman singer now living with her Wicked co-star in New York City, as he performs in Spamalot.

The pair met in December 2022 on the UK set of the film adaptation of the smash-hit Broadway musical Wicked, in which Ariana plays Glinda – the good witch – alongside Ethan as munchkin Boq.

Both couples announced they had split within a few days of each other back in July, with Ariana announcing her separation from Dalton just three days before confirming her new relationship with Ethan, who then filed for divorce from Lilly.

He cited irreconcilable differences and asked for joint custody of their newborn son.

Lilly has since damned Ariana in a series of disparaging interviews, telling Page Six the songstress is ‘Not a girl’s girl’ and adding blisteringly that ‘My family is just collateral damage’ to her.

Speaking exclusively to DailyMail.com, the estranged spouse of the Broadway star said she is determined to move on with her life as a single mother, without her ex-husband.

‘I am focused on rebuilding a life for our son,’ she said. ‘This is what I am trying to do and this is my only focus.’

Lilly’s admission came as a source close to Ariana and Ethan claimed that the singer ‘hung out’ with Lilly and her newborn baby multiple times before her romance with her co-star was revealed – and even told those around her how much she ‘wanted a baby one day’ after bonding with Lilly and Ethan’s.

An insider close to Lilly and Ethan alleged to DailyMail.com that Ariana and Ethan’s relationship has taken a brutal toll on the new mother – who spent time with the singer on multiple occasions while visiting her husband on-set in London.

Stunner: The two-time Grammy winner wore her blonde hair in a sleek ponytail, reminiscent of her trademark half-up, half-down hairstyle that became just as famous as her when launching her music career in 2014

Turning heads: The r.e.m. beauty founder first met her beay on the set of the film adaptation of the smash-hit Broadway musical Wicked, in which she plays Glinda – the good witch – alongside Ethan as munchkin Boq

Signing: Ariana Grande signs autographs for fans at the Spamalot premiere

Ariana and fans: Ariana Grande interacts with fans at the Spamalot premiere

Ariana’s dress: Ariana Grande steps out with a strapless black gown and a black coat at the Spamalot premiere

Signing: Ariana Grande signs autographs for fans at the Spamalot premiere

Stunner: Ariana took to her Instagram to share sweet snaps from teh evening

Pose: Ariana looked like an Old Hollywood movie star

Big night: Ariana and her friends took a snap in the theater

Elegance: Ariana exuded elegance during the gorgeous Big Apple evening

Performer: The Bang Band singer’s partner, who starred as the titular character in the SpongeBob SquarePants Broadway musical in 2017, will portray both Prince Herbert and the Historian in his latest production

‘Lilly hung out with Ethan and Ariana so many times,’ the insider claimed. ‘Ariana met their baby and even held him.

‘They had dinners together in London – and Ariana told Lilly that she wanted to have a baby one day and that she couldn’t wait to start a family.’

According to the source, Lilly and her son traveled to London to visit Ethan on the set of Wicked this April – just eight months after the baby’s birth.

The insider claimed that Lilly discovered her husband had been having an affair with Ariana after that visit – but that she and Ethan made the decision to try and ‘put it behind them and work on their marriage,’ only for her to later discover that he had continued his romance with the singer.

Low profile: For his big night, he was seen looking sharp in a black suit, coordinating tie and a white dress shirt; the father-of-one, 31, and Grande arrived separately at the event and did not pose for photos together at the red carpet ahead of the show

‘There was a period when they were all going to try and work on their marriages and put the whole thing behind them,’ the source said.

‘She thought they were happy. But that did not work out [because Ariana and Ethan] kept the affair going despite [that].’

The insider said that Ethan then blindsided his wife by filing for divorce, insisting that the decision to officially end the marriage was made entirely by the actor.

Ethan and Lilly – who was his high-school sweetheart – got married in 2018 before welcoming a baby boy in August 2022.

He gushed about his soon-to-be ex-wife on their fourth wedding anniversary three months later in November, with Ariana liking the since-deleted post.