Mary (Debra Winger) and Michael (Tracy Letts) are a married couple. They live together, but are estranged from one another. They are both having long-standing extramarital affairs-she with Robert (Aidan Gillen) and he with Lucy (Melora Walters). Their lovers have both emphatically demanded they break up the marriage and Mary and Michael have vowed that they will do so after a visit from their son, Joel (Tyler Ross), and his new girlfriend, Erin (Jessica Sula)..