Rena comes to the city to care for her daughter before childbirth. Her anxious pregnant daughter takes her frustration out on her husband and eventually even bans him from masturbating. Unable to contain his pent-up desire, he spies on Rena in the shower from the changing room. She notices him and, feeling sorry for how harshly her daughter treats him, gently embraces him and touches his cock at the brink of release. The forbidden comfort develops into repeated breeding sex between the adult son-in-law and his mother-in-law.