StepSis got caught wanking by the parents and has been banned from masturbation. Since she's so pure, she's going to follow the rules and not touch herself. But stepsis gets super horny one day and stepbro tells her about a loophole in the rules. If stepbro does it, it’s not technically masturbation, or sex, so she can still stay a virgin and cum, she just needs a little help. Oh what a wonderful selfless stepbro for doing this for stepsis... It makes alot of sense actually, and step-mommy and step-daddy will never suspect a thing.