Ben (BRUCE WILLIS) and Katie Jordan (MICHELLE PFEIFFER) have been married for fifteen years and seem like any other happily married couple. Yet that's been nothing but a charade for their kids, Josh (JAKE SANDVIG) and Erin (COLLEEN RENNISON) who may have a hint at their parents' problems, but aren't aware that they're nearing a divorce.
In fact, when the kids head off to summer camp, their parents separate. While Katie, a crossword puzzle creator, stays home and discusses relationships and men with her friends, Rachel (RITA WILSON) and Liza (JULIE HAGERTY), Ben, a novelist, moves out and does the same with his friends, Stan (ROB REINER), Rachel's husband, and Dave (PAUL REISER), his literary agent.
As the two reminisce about both the good and bad times of their relationship, Ben, the optimist, hopes they can get back together. Katie, however, who's succumbed to years of pent-up domestic frustration and irritation over Ben's idiosyncrasies, isn't so sure.
That's especially true since whenever they try to reunite they end up fighting again, and also because she's started seeing Marty (TIM MATHESON), a divorced friend. With Josh and Erin soon returning from camp, Ben and Katie must decide whether they'll give their marriage one more try, and if not, how they'll break the news to their kids.