Phyllis goes on the defensive after Jill berates her for sleeping with Billy She caught them in bed together and was stunned when she realized they were having an affair, and now, Jill (Jess Walton) will confront Phyllis (Gina Tognoni) about her cheating on Jack (Peter Bergmann) with none other that his brother-and Jill's son-Billy (Jason Thompson) on The Young and the Restless.