Kristen Stewart Thong PHOTO: Robert Pattinson's Ex 'Wows' in Sexy 'Clouds Of Sils Maria' Movie Trailer [WATCH]

Robsten's no longer together - but Robert Pattinson and Kristen Stewart are both very busy with their own separate movie careers!

The former "Twilight" lovebirds both attended the 2014 Cannes Film Festival to promote different projects. They were NOT spotted together - in fact, rumors suggest they intentionally avoided one another throughout the entire event.

Anyway, one of K-Stew's upcoming films is entitled "Clouds of Sils Maria." A Wiki plot description reads:

Maria Enders (Juliette Binoche) has a successful acting career and a loyal assistant Valentine (Kristen Stewart), but when a young actress (Chloe Grace Moretz) interprets a role in a new movie - the same role which made Enders famous - her world starts to crumble. Haunted by her past life, she withdraws herself along with her assistant to the Swiss town of Sils Maria.

Sounds like an interesting drama - the official movie trailer was just released online. All three ladies steam-up the screen, especially 24-year-old Stewart! At one point during the racy flick, K-Stew flashes her booty in a skimpy black thong! Check it out:

Wonder if that caught 28-year-old R-Patz's attention!

The film is currently competing for the Palme d'Or at Cannes - do Mstars fans think Olivier Assayas' current masterpiece stands a chance?