Mother Exchange 9. Melissa Stratton has an unhealthy attraction to her stepson Robby. After seeking counseling, she discovers a secret "support group" of sexy stepmoms who suffer from the same obsession. However, rather than trying to control their taboo urges, these troubled ladies seem to embrace them fully, even plotting to "exchange" stepsons with each other while keeping the secret from their husbands. What could possibly go wrong?.