Mila Kunis with Ashton Kutcher

Mila Kunis with Ashton Kutcher

Ashton Kutcher and Mila Kunis joined Princess Beatrice and her boyfriend for a trip to the South of France.

The Hollywood couple and the British royal and her partner Dave Clark - who is friends with the 'Two and a Half Men' actor - all went to Saint-Tropez together over the weekend for a mini-break.

The foursome were spotted taking a walk along Pampelonne Beach in the sunshine and were chatting and laughing.

Ashton and Mila were then joined by their loved-up pals on a yacht which took the group out to sea so they could drink and eat in private.

Mila, 29, and Ashton, 35, have been living in Hampstead, north west London, for the past several weeks while she shoots new movie 'Jupiter Ascending' and since they arrived in the UK capital they have been spending a lot of time with Dave, 30, and 24-year-old Beatrice - who is the daughter of Sarah Ferguson and her ex-husband Prince Andrew.

One evening last month, the quartet enjoyed dinner at the Duck & Waffle restaurant on the 40th floor of Heron Tower, before moving on to enjoy tequila cocktails at the nearby Callooh Callay bar. They ended the night at the John Salt bar in Islington.

Beatrice, her sister Princess Eugenie and their mother Sarah are believed to be attending the wedding of Tamara Ecclestone - the daughter of Formula 1 boss Berne Ecclestone - and Jay Rutland taking place at the luxurious Grand Hotel Du Cap-Ferrat in Saint-Jean-Cap-Ferrat on the French Riviera today (11.06.13).

Other guests rumoured to be attending include Paris Hilton and Rosie Huntington-Whiteley, while entertainment is being provided by Sir Elton John, Lionel Richie and DJ Mark Ronson.