[Poriuretan] Kotatsu-loving Step-siblings

A young woman in a schoolgirl uniform argues with a man at a kotatsu, pleading to keep it warm while he insists on taking it away. They quickly transition to the heated table where she leans over, sweating profusely and displaying an ahegao expression as they begin their passionate, sweaty encounter. The intimacy escalates into explicit, messy sex with both characters covered in fluids, engaging in vigorous intercourse as dialogue suggests incestuous dynamics.