Udachnyy obmen (2007)

Dasha and Dima are married for five years and from the side their life seems to be all right: they are wealthy enough and have everything their family needs - But it's not insufficient for them to be happy: the couple's relationship has always been boring and predictable, with no sign of romance at all - One day Dima's twin brother Kirill comes from another city to see him. In a while Dasha occasionally overhears brothers' talk: her husband offers Kirill to take his place for the coming vacation and Kirill accepts the proposition. So, Dasha joins the game.