Part 2 - Curious Echigo No. 3, despite my parents being around, seduced my relative.

Wait, wait! A cute girl (19 years old) is too curious, peeking into her parents' eyes and seducing me, a relative! If I cross the line, will I be unable to go back? But I want to have sex with a cute girl...! Oh no, I can't stand it anymore, I'm going to give in to temptation! The third in a series of temptations one after another!