Wife is in a serious accident and in review of the medical history the husband discovers not only a long term affair but something much more devastating.
This is the third in a triptych of "Couples" stories about three couples at a function, (1) Eve & Adam "Eve's Choice" about newly weds, (2) Carol & Rob "Cheese & Clicks" about two people meeting for the first time, and (3) Natalie & Alan about the long-divorced parents of the Bride. You do not need to read the first two to read the third.
Mark and Dawn are vacationing in Mexico to try and rekindle the passion. But Dawn doesn't seem to be as interested. Their host, Maria, stops in to talk to Mark but ends up in bed with him instead.
Tamara's older husband promised to take her on a trip to Europe if she shed some weight and toned up her already beautiful body. He employed a young male personal trainer to help her. When he reneged on the deal, she looked to the young personal trainer for her revenge.
A habitually cheating mother is caught cheating again, this time by her high-school-age son. In order to protect her second marriage from ending in divorce too, he punishes her to teach her a lesson. Then he takes over keeping her in line... his way!