Shinji tries to make up with his wife who is sulking and lying down after a small fight. While kneading her plump, meaty ass, he raw creampies her with a "zubozubo" sound. When he tries to kiss her, feeling good from the tighter-than-usual squeeze... it turns out the person there was his wife's sister! "I-I'm sorry, sister-in-law!" The sister-in-law forgave Shinji, who was prostrating himself and apologizing, but she couldn't suppress her body that had begun to ache.
