Two couples, friends since college, heat up a cold, snowy Christmas Eve by swapping partners. Uptight Bill has always lusted after his wife's best friend Penny, but as a loyal husband he never even considered making a move. Kim, Bill's wife, maybe a conservative wife and mother now, cuts loose and relieves her wild college days by indulging her desires with Penny. Meanwhile, Kyle, Penny's husband, can't believe he's finally going to get to bed curvy Kim, a woman he's always had his eye on.