Dek (Ifans) and Shirley (Henderson) live together with 12-year-old Marlene (Atkins), her daughter by the sexy, delinquent Jimmy (Strachan) who disappeared years ago and hasn't been heard from since. Decent-but-dull Dek loves Shirley, so much so that he humiliates her by proposing without warning on national television. Like every other person Shirley has ever met, Jimmy witnesses Dek’s TV proposal and he returns to town, convinced that his nerdy rival doesn't stand a chance against a renewed romantic assault from the great love of her life. While Shirley seems destined to succumb to Jimmy's charms, he hasn't reckoned on the formidable resistance from their daughter Marlene, his sister Carol (Burke), her estranged husband Charlie (Tomlinson), their sons Emerson and Lake, Carol's daughter Donna, and her boyfriend Donut. Nor could he anticipate a heroic, last-minute challenge from the mild-mannered, lovesick Dek.