At a resort, a couple was approached and it turned out to be siblings. The sister was a slut who changed men frequently, and the brother was a virgin. A game of baseball was proposed where if the brother couldn't get an erection from seeing his sister naked, he would win a prize. The siblings played games like deep kissing and vibrator guessing, with options to avoid taking off clothes. As they played, the atmosphere became more intimate. The brother was fully aroused, and they both became aware of each other. Eventually, they decided to cross the line and become "man" and "woman" instead of siblings. This is a documentary of the siblings crossing the line!
