Fourplay follows the romantically entwined lives of a TV writer, producer, actress and makeup artist. Ben Greene (Binder) is an American comic writer who comes to Britain to write for a show, "Telford Gate". The star of the show, Carly Matthews-Portland (Hemingway) is married to the producer, Allan (Firth). Carly decides to help Greene, by setting him up on a date with a French makeup artist, Fiona Delgrazia (Irène Jacob). As the movie progresses, the lives of the couples get more entwined and they each decide if they are in the right relationship or not.