Imogen Poots shows breasts and part of her ass as she is having sex in Mobile Homes. The scene is pretty similar to the Frank & Lola scene in that it takes place early in the movie (2nd scene) and is set in a motel room. Unlike that scene, this one is well lit and you actually see Imogen have sex for a bit but the scene is a lot shorter.
A few minutes later, Imogen has sex in a pool and she shows part of her ass from the side underwater.
Mobile Homes is currently playing in Cannes.