I Can Never Tell My Wife… I Got My Mother-in-Law Pregnant… - I Lost Control and Creamed Her Over and Over on a One-Night, Two-Day Hot Springs Trip - Rin Azuma
Two years into their marriage, the protagonist's in-laws are worried that the couple still hasn't conceived a child. To help fulfill their wish, they arrange a two-day, one-night fertility-focused hot spring trip. The father-in-law says, "You've stayed abstinent as promised, right? Make it happen on this trip—I want to see a healthy grandchild soon," placing high expectations on them. However, those hopes are dashed when the wife falls ill and takes to bed. After a month of enforced abstinence, she grows restless and tormented, unable to sleep at night. One late night, the protagonist wanders the inn and accidentally catches sight of his stepmother bathing. In that instant, the story takes a dramatic turn.