The former Made In Chelsea star looked tanned, toned and just all-around gorgeous in a one-shouldered Zimmermann dress as she joined Pro Green at INK in the West End on Wednesday night (4 September).
Millie, 23, arrived at the club alongside MIC pal Rosie Fortescue. The girls had earlier attended the launch of Very.co.uk's new collection at Somerset House, but made sure to leave in good time to get to INK for its big opening.
Pro Green looked suitably excited as he welcomed celebrity guests including Emeli Sande, Diana Vickers, Zoe Hardman, Carl Barat and Wretch 32.
Laura Whitmore was also on hand for a DJ set.
INK is a tattoo-inspired venue at 1 Leicester Square, created by Pro Green – real name Stephen Manderson – and brothers Jon and Gerry Calabrese. It features artworks from tattooists Nikole Lowe and Neil Ahern, alongside graffiti murals and bespoke neon sculptures by Chris Bracey to represent the East End scene.
The idea is an East End club in the heart of the West End.
Star guests sipped on cocktails and enjoyed canapés including Hoxton Gin cured salmon, goat cheese beet root and mini scotch eggs.
According to a source, it was Millie's first time seeing the club finished and she joked to friends she'd probably be spending a good deal of her married life inside it!
Pro Green popped the question to Millie during a romantic holiday to Paris on 25 March. At the time a thrilled Millie said: "If I could scream loud enough for the whole world to hear then I would."
The couple have been keeping details about their nuptials private, but it seems the big day could be soon as Millie celebrated her hen do with friends including Rosie and Binky Felstead last month.