My sister-in-law's seductive advances lead to a forbidden physical relationship. "Just once..." The woman's possessive desire seeps into the man's vulnerable heart. His morals crumble like a dam breaking, unable to escape the infidelity swamp, forgetting his wife... forgetting himself... being taken advantage of... Every time they engage in this forbidden affair, they become increasingly consumed by the thrill of the taboo. "If only I hadn't known... My sister-in-law was this slutty..."