After learning that his best friend's parents are getting a divorce, Justin fears the worst when he sees his mother kissing Santa Claus--really his father in a Santa suit. Justin concludes that if Santa rewards "nice" boys and girls, then the only way to keep Santa away from his mother on Christmas Eve is to be naughty. Justin transforms into a holiday problem child, starting by getting in trouble at school and then taking out his revenge on a sidewalk Santa. As Christmas nears, Justin fears that Santa will still appear, and when his father is trapped out of town in a snowstorm, Justin is forced to defend his home on Christmas Eve from the Ho-Ho-homewrecker.