Harry Styles has joked he feels “old”.

The One Direction heartthrob celebrates his 19th birthday today.

Despite being younger than bandmates Zayn Malik, Louis Tomlinson, Niall Horan and Liam Payne, it seems the curly-haired hunk is worrying about his age.

“I feel olllllllllllldddddddddddd. (sic),” he complained on Twitter.

Luckily, Harry managed to take his mind off grey hairs and wrinkles with a night out.

The singer hit London’s Groucho Club with a group of pals that included his 33-year-old ex-girlfriend Caroline Flack and another former flame, model Cara Delevingne.

The party were snapped outside the venue last night before moving on to the city’s Gerry’s Club.

His bandmates didn’t join in the festivities on Thursday night, but Harry and Louis did enjoy a soccer game during the day.

The boys donned personalised shirts to hit the playing field with some friends.

Niall made up for his no-show at Harry’s birthday party by taking to Twitter to wish his fellow musician all the best.

“Happy birthday to my youngest brother @Harry_Styles have a good one me aul son (sic),” he wrote.

Hoards of fans took to the social networking site to wish the musician a happy birthday.

However, it seemed Harry’s ex-girlfriend Taylor Swift had other things on her mind rather than publically congratulating the star.

“3am. Jet lag. Whyyyyyyyyyyyy. (sic),” she commented on her page instead.