Like most people, Reuben Feffer (Ben Stiller) is at a crossroads in life. He is recently married and while on their honeymoon his wife Lisa (Debra Messing) commits adultery with a scuba instructor while wearing their flippers. Reuben walks in on the pair during their additional training. He returns home and while at a party he accidentally runs into an old classmate Polly Prince (Jennifer Anniston). They talk and agree to go on a date. However, the problem is Polly is a free-spirit and doesn't want commitment. Reuben is just the opposite, working in a risk assessment occupation and being anal retentive. Polly and Reuben date a little, argue a little and date a little until Lisa comes crawling back, begging for forgiveness. Now Reuben must choose between the two of them. Will his risk assessment formula help him make the right choice or will he end up unhappy?