The usually virile panama hat-wearing Bob finds himself too tongue-tied to ask out Lucy, the gorgeous girl he fancies at work. His friend and flat-mate Harry has the idea to organize a seventies themed party at their house that they can invite her to. But Harry is adamant that his ex-girlfriend Sarah doesn't find out about it. So when Bob makes the mistake of inviting her; the night doesn't quite turn out as either Harry or Bob had planned.