He says that he's fucking his aunt for about a year or so. Since he got divorced he went back to live with his widow mother and her single sister. She's 45yo, only 9 years older than him. She was always desperate to get a good fuck but too much conservative to look for what she wants, they live in a small town where everyone knows everyone. So they came up with this perfect plan. They both get laid and don't need to go and look for sex, they only need to be sure his mother is not at home to start another fuck therapy sessiom.