Louis Tomlinson feels ''old'' now he is 21.

The One Direction hunk - whose birthday is today (24.12.12) - still can't believe he has reached the landmark age and has taken to Twitter to share his astonishment at being the eldest member of the group.

In a series of tweets Louis posted: ''Ahhhhh I'm 21 !!


''Ahhhhh I'm old !!!!! (sic)''

Although Louis is worth around £100 million along with the rest of his band - Zayn Malik, 19, Harry Styles, 18, Niall Horan, 19, and Liam Payne, 19, - the singer from Doncaster, South Yorkshire, was thrilled when he received a novelty box of tea bags from hot beverage giant Yorkshire Tea as a present, who had added his name on the packaging.

He gushed: ''Thank you soooo much @yorkshiretea . Should have seen my face when I opened it. So very kind of you. Loveee x (sic)'', followed by a link to a photo showing a box of the tea with 'Happy Birthday Louis' printed where the logo is.

The group's official Twitter account also sent their birthday wishes to Louis, as well as wishing the fans a merry Christmas.

They wrote: ''It's Xmas Eve! & @Louise_Tomlinson's b'day! Happy b'day Louis! Thanks to everyone who designed Louis a card! 1DHQ x (Sic)''

All the boys, accept for Harry, were spotted arriving back in London on Friday (21.12.12) after their performance on 'The X Factor' USA final on Thursday (20.12.12) on Los Angeles.

Harry has been enjoying a romantic ski break with his girlfriend Taylor Swift in Utah, however the British heartthrob is planning to spend Christmas Day (25.12.12) with his family in the UK while Taylor jets off for some sun down under in Australia.