For this couple it's sink or swing.
Having met in college, American born Ellie (Mandy Moore) and her husband Alvin (Martin Freeman), are several years into their marriage. The heady sparks of lust and fun have sadly faded and they're left with the day to day normality of their everyday life. Advised by best friends, Peter (Jonathan Silverman) and Janet (Melissa George), who are having their own marital problems, Ellie and Alvin are desperate to 'spice things up'. Ellie hits upon the brilliant idea to mix things up with another couple - to have a 'consensual affair' within the confines of the marriage. Our couple embark on finding the ideal couple and begin to interview a plethora of perverse and quirky swingers. They finally settle on what seem to be the perfect couple and a night of insanity and hilarity follow.