Billie Eilish cheekily confesses she would have sex with Charli XCX on their raunchy 'Guess' remix.

(c) Terrence O'Connor

(c) Terrence O'Connor

The two pop superstars have joined forces on a new cut of the latter's extended 'Brat' track - and didn't hold back in the steamy lyrics.

Billie, 22 - who identifies as queer - sings: “Charli likes boys, but she knows I’d hit it. Charli, call me if you’re with it.”

In the music promo for the dance tune - helmed by Aidan Zamiri - the pair are seen mounting a pile of lingerie with Charli singing: “You wanna guess the colour of my underwear.”

At the end of the song, Charli, 32, sings “You wanna guess what me and Billie have been texting about... You wanna guess if I’m serious about this song.”

As well as having fun on the playful song, the pair have raised awareness for those from poor backgrounds and homeless girls who cannot afford essential items by donating the bras and knickers from the video to the I Support The Girls non-profit.

A press release notes that: "All bras and underwear used in the music video have been donated to I Support The Girls. ISTG collects and distributes essential items, including bras, underwear and menstrual hygiene products, allowing people experiencing homelessness, impoverishment or distress to stand tall with dignity."

Away from her music career, the 'Apple' hitmaker has been busy working on a number of film and TV projects since the success of her 'Barbie' soundtrack tune ‘Speed Drive’ last year.

Charli has contributed to the score for the A24 film ‘Mother Mary’ with studio wizard Jack Antonoff and is also producing original music for Benito Skinner’s series ‘Overcompensating’ on Prime Video.

The singer will also star in Daniel Goldhaber remake of 1978 cult horror film ‘Faces of Death’.

Charli recently confessed she doesn't "envisage" herself "making music for ever".

The 'Girl, so confusing' singer admitted she is keen to "flex my creative muscles on other areas".

She was quoted by The Sun newspaper's Bizarre column as saying: “I would like to flex my creative muscles on other areas. I don’t envisage myself making music for ever.

“Maybe I will in some capacity, but I just feel like there are other creative areas I really want to explore.”

She said of her debut acting gig: “I was a fan of the original movie.

“I saw that this film was being remade by a director, Daniel Goldhaber. We met and we spoke, and he was like, ‘You should be in it’. I was like, ‘Wow, that’s crazy’.

“I really got the bug from that.”

The film will follow a similar format to the original as it’s set to be presented like a documentary detailing the most horrific murders of the time. While most of the footage is staged, the use of real footage proved controversial and led to it being banned in multiple countries.