MIAA-057 My brother-in-law likes to masturbate and the ending

My younger brother (me) is beautiful but has been sexually stimulated all day despite being bullied by my stubborn sister. It seems that she will soon get married, but I know that my sister used to be a yankee and a pervert in the past. I will use this as a joke to force my sister to do it! Until now, I have secretly watched sex with men, and it is time to present my research findings on how to make my sister feel and ejaculate.