I decided to teach my younger sister how to swim because she hates swimming lessons. - I can't stand the swelling of my growing breasts and get an erection and can't teach them well! - Then, my younger sister noticed that I was panicking due to an erection and said, ``Please tell me quickly, how can I get rid of this (erect penis)?''. - My younger sister can't hold back and asks me to fuck her, but she says, ``Of course...''. - I was despairing that this was the end of our brother-sister relationship, but my sister, seeing how disappointed I was, suggested, ``Well, if we just rub it together...''