He caught a glimpse of his wife's mother changing her clothes. The tight corrective underwear she was wearing to combat middle-aged weight gain was stretching her body, and her magnificent huge breasts were about to pop out. The son-in-law swallowed his saliva at the sight of her lewd body, which was completely different from her usual ladylike appearance. He couldn't let her go astray. He tries to use all his rationality to forget, but he can no longer bear the constant image of his stepmother getting changed and he ends up attacking her.