IENF-244 A female student's younger sister took pity on my useless self and agreed to let me do 'so-ko' (frottage) with her, but we both got too into it. Her pussy was soaking wet! So I slipped it in! "What!? It's inside?" But I couldn't stop and ended up

The younger sister of a female student is sleeping with her panties fully exposed. The excited older brother immediately grabs his dick for a jerk-off session upon seeing his sister like that. However, he is quickly noticed, and the brother who lusts after his sister is treated as a pervert. But gradually, she starts to feel sorry for him. She offers to help, but the brother can't seem to cum. The sister, fed up with waiting...!