A man happens to be alone with his wife's mom friend in a mixed bath at a hot spring inn. - A man gets an erection even though he thinks he shouldn't, and tries to masturbate without being noticed, but he finds out. - However, even though she thought she would be looked down upon, her mom friend seems to be happy to be seen as a sexual object and wants to have sex with her. - Then, when she saw the man getting excited by his raw dick, her breathing became heavy, and she couldn't help but reach for the dick...