My younger sister has recently grown into an adult-like body. When I looked at the casual panty shot and the sweet chest of the guard, I couldn't help but get an erection! Then he said, ``Brother, maybe it was me who got you excited? '' and I couldn't help but think, ``You're excited about me too!'' ” to the situation where he retorted! It is true that I, a virgin, had an erection. But my younger sister was my younger sister and seemed excited by my erection... In the end, the ugly argument crosses a line that should never be crossed... They both think it's just incest for one day.