During summer vacation, my sister's friends came over to our house while our parents were away and we had a study session. The girls, who are curious about sex, purposely show me their panties and enjoy my reaction. They sneak over when my sister is away and want to learn all about my dick. My dick reacts immediately to the panty shots of the girls, who are too Ke'ai and erotic, and I sneakily do it with all of them.