My mother remarried and my new stepfather and step-sister are hardcore nudists, so I can see my step-sister's tits and ass every day! I can see her pussy and get a full erection! I was encouraged to join the nudists, so I reluctantly got naked, but my step-sister immediately noticed my erection and started teasing me...I can't stand being naked with both of us! She asked me to give her a massage, and while I was close to my step-sister, I forcefully inserted my erect penis into her! I didn't care and just shook my hips and came inside her many times!