While many male couples are sexually exclusive, others have honestly negotiated a nonmonogamous relationship. In order to do effective clinical work with male couples, therapists have to be open to moving beyond traditional theories inherent in family and couples therapy regarding extradyadic sex. One way of achieving this is to recognize countertransference, which is often based on cultural biases regarding monogamy. This chapter reviews the research on male couples and sexual exclusivity and suggests a variety of ways that therapists can be better prepared to work with male couples around the issue of sexual exclusivity and nonexclusivity.