After both being jilted at a Christmas party during their senior year in high school, best friends Kathi and Greg make a pact; that if they are still single on Christmas when they are 35 years old, they will marry each other. 16 years later, history repeats itself, when they are reunited at another Christmas party after both having been freshly dumped. After some drinking, and crying on each other’s shoulders, and more drinking, they decide to go for it. They both profess their undying love for one another, and plan to get married by Christmas.

 

The next morning, Kathi awakens with a new lease on life, giddy about the prospect of marrying her lifelong best friend.  Greg wakes up with a splitting headache and no recollection whatsoever of the events of the night before. At first annoyed, Kathi decides that their decision is the right one, and tries to let Greg go.  But when Greg’s ex attempts to rekindle old feelings, Kathi finds herself competing for Greg's affection, and they both begin to wonder whether or not their friendship can survive the test of true love.