Wasp (movie, 2015)

Having left England for a romantic escapade in the South of France, Olivier and James invite Caroline along at the very last minute. The trio arrives in a little Provencal village, somewhat cut off from the world. Though everything seems calm between the pool, sunshine and a village visit, Olivier finds himself more and more intrigued by Caroline. A tension of sexual jealousy and possessiveness will then escalade between the three of them.