The "One Thing" hitmaker gate-crashed Cara Delevingne's big sister's ladies' night on Saturday, dressed as a member of the '90s band Hanson.
The hen's night was held at London's Groucho Club and whilst the 26-year-old model's theme was retro, she got a little more than she had originally bargained for...
A source revealed the night's details to The Sun newspaper, saying, "Harry rocked up to the club with Nick Grimshaw and quickly stole the show with his getup.
"'MMMBop' was requested from the DJ and Harry launched into a sexy dance for Poppy and her mates, who were in fits of giggles. He was entertaining everyone for the evening."
Poppy will be marrying her long-term love James Cook and what better way to wave goodbye to being single than with a send-off from Styles?
Yet, the British heartthrob was still not done entertaining. After his Hanson performance, he later moved on to the fancy dress costumes that were available at the club. And his next choice... a Nelly the Elephant head.
Poppy's party was filled with beautiful women, including Georgia May Jagger, Jaime Winstone, Sienna Miller and Alexa Chung, and we are sure the "Best Song Ever" singer enjoyed himself surrounded by models, including Cara Delevingne — who he has previously been romantically linked to...
We wonder what rumored love interest Daisy Lowe thinks about the event?
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