14/08/2014 16:45 BST | Updated 20/05/2015 10:12 BST

Suki Waterhouse And Bradley Cooper Are All Loved Up At Serpentine Gallery Summer Party

Fresh from his appearance at Glastonbury festival, Bradley Cooper got suited and booted for the Serpentine Gallery's annual Summer party in London's Hyde Park on Tuesday night.

The 39-year-old actor was joined by his 22-year-old model girlfriend Suki Waterhouse and in case you were wondering, they're still loved up.

Suki wore a blush pink, plunging Burberry dress and chunky print sandals from Topshop while Bradley teamed his suit with an unbuttoned pale blue shirt and aviator Ray Bans.

But Brad and Suki weren't the only stylish A-listers at the event. They rubbed shoulders with Pharrell Williams (who looked dapper in a Brioni jacket paired with his his signature head gear), Keira Knightley and her husband James Righton, Alexa Chung, Cara Delevingne, Princess Beatrice, Lily Allen and Naomi Campbell.

While all eyes were on Bradley and Suki - it was Alexa, Keira and Cara who pulled out all the sartorial stops. Alexa and Cara both opted for classic black - Cara chose a floor-length design by Mulberry but in true 'It Girl' style, Alexa wore her dress with flats and a sexy red lip (she's still doing the ombre hair thing too.)

Keira also looked stunning in a multi-coloured floral applique dress by Chanel complete with pleated sheer skirt and metallic heels. Hands down, this is one of her best party looks yet.

As for Naomi Campbell and Gemma Arterton's statement-making ensembles? Let's just say these ladies know exactly how to master the art of a sexy red two-piece.

LOVE AN A-LIST GATHERING? Take a look through this gallery to see all the celebs at the Serpentine Gallery's legendary annual summer party last night.