Step sister's wet and naked pantyhose tease on my dick

My new step sister has a weird fetish. She\'s always walking around the house almost naked, showing off her big ass and tiny panties. I\'m not into it, but my dad thinks it\'s hilarious. When she\'s around, I can\'t help but stare at her. But when she starts giving me a blowjob, I can\'t resist fucking her hard.