My wife's sister is a slut in need of cock

My wife loves her sister very much, to whom she is very close. this is probably why the poor girl has a hard time realizing that her sister is in fact a slut who is after my dick. i tried to explain it to her but in vain. the arsonist doesn't hesitate to use her feet to rub my cock in my shorts. she even introduced her hand squarely to jerk me off and suck my rod when her sister is not around. what is the point of finally fighting? i'm going to do it.