I always wished I had a stepsister growing up that was willing to fuck! Although this is fake I do know that it does happen. I think it's ok, It's safer than fucking strangers and its a good way to learn. The closest I ever got though was a threesome with my friend and his stepsister she caught me and him jerking off to porn so she started masturbating with us then she wanted it so bad and It was amazing! Too bad we only did it once!