Billie Eilish has sparked major concern from fans after showing off her bruised arms covered in bite-marks.

The Skinny songstress, 22, took to Instagram this weekend to share a series of selfies – including one which showed her in a microscopic pink bikini and wrapped in a towel while celebrating the fourth of July with fireworks aplenty. In the snap, Billie scraped her dark hair back into a ponytail and stuck out her tongue while clutching a firework between her fingers to let the colourful sparks fly.

She wrapped herself in a cream towel held just below her bust, nearly spilling out of a pink halter-neck bikini top with a cartoon face drawn over one cup. Adding silver hoop earrings to her ensemble, Billie looked unconcerned by the firework’s proximity to her person.

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But later snaps proved worrying for some fans – Billie crossed her arms over her chest to show off matching bite-marks on both her tanned forearms. They looked freshly made, though later they turned into deep round bruises while Billie posed with a pal for a mirror selfie.

Billie Eilish
Billie Eilish posted a very rare bikini snap – but fans were worried

She donned a black t-shirt with the number 23 on the front, adding silver dog tags around her throat and a pair of glasses as she squinted at the camera, rocking a middle part and scrunching her lips for the camera. Later, Billie appeared to strip off completely as she posed for an intimate snap with her hair falling into her face.

In lieu of a caption, Billie simply posted two firework emojis alongside her post as fans flooded the comments section to brand her a “hottie” – though others were more concerned about the bites. One fan said: “Wait are those bite marks?”

Billie Eilish
She showed off matching bite marks on her arms

“Is she… okay? Those bites look nasty,” another follower commented. Others simply wanted to share their admiration for the Bad Guy hitmaker, with one penning: “Billie living her LIFE! What a time to be alive.”

“So pretty I might actually stop breathing,” someone else agreed. Another social media user said: “I’m on my knees!” Another posted: “The second pic made me gasp.”

The rare bikini snap comes after Billie was branded a “nepo baby” when fans spotted her mum Maggie Baird in an episode of Friends. She played a small role in season six episode The One Where Joey Loses his Insurance, playing a casting director in the 1999 episode.

Billie Eilish
The bites blossomed into bruises on her arms

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But Billie’s brother Finneas, who works on her music alongside her, hit out at the criticism, writing: “Ah yes, the classic, one day of work on one episode of Friends to make someone rich and famous- the whole gag of this video is none of you had any idea at all who she was.”

Maggie has also appeared in shows like The X Files, Charmed and Bones, while the siblings’ father Patrick O’Connell has starred in Iron Man, The West Wing and General Hospital.