Real brother fucking his sister at home

«my sis and i got caught fucking one day by our mom she was not happy with us and told us about getting pregnant and all then sis told her she was on birth control so she is fine. then mom says do it in your rooms not in the family room your dad might caught you and he will have a fit.
one day mom asked me how long have you two been having sex i told her about nine or ten months. she says that long i said yes why do you ask she says i haven't had sex for over a year your dad is not interested in me anymore. i said well we can fix that if you want to she says i cant have sex with my own son. i said why not you know i am fucking my sister and you didn't get to upset with us at that time. well you two are young and she is on birth control so i saw no real harm. a week later mom said were you serious about have sex with me i said yes any time you want. she says she wants to have sex so we have been fucking now for over ten years. mom pussy is so good.»