Planned to Jerk off on His Stepsister's Ass, but as Always, It Ended with a C

Stepsiblings Mark and Emma have always had a secret desire for each other. One day, Mark decides to act on his fantasy by planning to jerk off on Emma's ass while she is asleep. He carefully sneaks into her room, undresses himself, and positions himself behind her. As he starts rubbing his erect member against her tightly-clenched cheeks, he begins to moan in pleasure.However, just as he is about to cum, Emma suddenly wakes up and starts to scream. She turns around, her eyes filled with horror and disgust at the sight of her stepbrother's exposed genitals mere inches from her face."What the fuck are you doing?" she shouts, trying to push him away.Undeterred, Mark grabs Emma's wrists forcefully and pushes her back down onto the bed."I don' n't think this task is..."