The Soho spot, which features raunchy shows with topless dancers and acrobats, is popular with the rich and famous.
As One Direction fans know, Harry's birthday was actually on 1 February but a showbiz party is better late than never.
WATCH all the stars arrive in our live stream above which kicks off from 8pm on Monday.
He's got big baby blues
And Jagger-like moves
He has the ability to make wombs explode
He knows how to
twerkwork a crowd
He's not a squeaky-clean boyband member
He never displays diva behaviour
He is the most beautiful crier
Beaten only by Cheryl Cole.
*pokes the screen*
He loves his boys
But not as much as he loves us
Either that or he really likes saying "elephant juice".
His vast musical skills
His athletic prowess
Because he's worth it.
His smouldering stare
He makes a hot geek
We <3 Marcel.
And he makes an even sexier walrus
He's as smooth as silk
He's got swag
And bags of it too.
And he's just too adorable for words
Honey Boo Boo eat your heart out.