The Mademoiselle's Stallions(2013)

Original title: Les Étalons de Mademoiselle

Maude is a beautiful young woman with a carefree and liberated sexual attitude. The same cannot be said for her best friend, Charlotte, who's extremely shy around boys. The girls go on holiday together to England, where they stay with Charlotte's family. Unfortunately, Charlotte's mother gets off on humiliating her, by being a promiscuous, cheating slut. For Maude, it is too much, so she devises a plan that will allow Charlotte to both ... experience the ecstasy of passionate sex and get back at her bitch of a mother. What transpires is unbridled depravities, wild threesomes and mini gang bangs!