Kate Moss partied with Madonna at her birthday party over the weekend. The 40-year-old supermodel joined the 'Material Girl' singer in celebrating her 56th birthday at a lavish 1920s-themed celebration in a private villa in Cannes, France, where the pair were pictured cosying up together in revealing flapper outfits. Madonna posted the photo of herself wearing a beaded black dress next to the iconic model on her Instagram account yesterday. She captioned the image: "Bow down Bitches! #whatitfeelslikeforagirl.(sic)" The 'Holiday' singer also shared a shot of partygoers posing in front of giant 'M' and intertwined with pink feather boas, who were clearly enjoying their evening. She wrote: "House of M! House of Fun! La Vie en Rose! #unapologeticbirthdaybitch." Madonna also shared a picture of her youngest son looking dapper in a black tuxedo. She wrote alongside the picture: "My escort for the evening! #swag #boom #livingforlove.(sic)"