Rachel had stayed behind after volleyball practice to get a bit of extra fitness training done, so by the time she hit the showers everyone else had gone home and she was all alone. The sound of the water and her own singing made her oblivious to Dildo-Jerome's approach and he was able to stand behind her, stroking his enormous cock for over a minute, allowing his scent to invade her body and subtly prepare it for his attack, all without her noticing.
Rachel had just started to think about how nice it would be to have a cock between her legs right now when Dildo-Jerome decided to make his presence known by granting her silent wish. He shoved his cock straight into her soaking wet pussy and the shocked Rachel stumbled forward into the shower wall. The tip of Dildo-Jerome's cock was still inside her and a second thrust pressed Rachel's face and breasts against the tiles. She tried to call for help but the only sound that would pass her lips were moans of pleasure. She doubled her efforts by raising her voice and she managed a scream but that too only conveyed the ecstasy she was feeling. She gave into the pleasure and allowed the stud to pound her against the cold tiles to an explosive orgasm. She screamed her pleasure, fireworks bursting in her eyes but Dildo-Jerome held off with a remarkable display of control as Rachel's spasming cunt tried desperately to milk his cock, for he was saving his corrupting seed for her ass.
"Oh god, so good... so.. fucking.. good," panted Rachel and then she felt the strangers cock press up against her forbidden hole. "What are you doing?!"
"I want to bestow upon you a special gift." he replied.
"Gift? I hardly consider a cock up my ass to be a gift!"
"Thats not what I meant, but I'm sure you'll enjoy that part anyway." Dildo-Jerome pushed against her anus a little harder and his cock, lubricated with her juices, slid gently in. Rachel moaned. Dildo-Jerome was right. "I'm giving you the opportunity to become my Master's mistress," he continued as he gently fucked her ass, "Once I cum inside you your transformation will begin. In order to become the Mistress you're body will need to be molded into the very image of his lust and your mind must become as perverted as his." Dildo-Jerome started to fuck her harder and raised his voice above her growing moans. "All of his perversions, kinks and fetishes will become yours and your body will be a temple devoted to their fulfillment. When your mutation has finished you will be a filthy-minded nympho-slut and our Master will be pleased! Now take it! Take my seed and become the slut you were always meant to be! AAAAAAHHHHHH!!" Dildo-Jerome roared and his cock erupted a torrent of seed into her bowels. Rachel came even harder then before, screaming herself hoarse until her legs gave way and she fell to the floor. She felt something plastic shoved into her gaping asshole and Dildo-Jerome spoke one final time.
"The changes will take a couple of days. During that time my seed must remain inside you. Do not remove this plug!" and then he was gone. Rachel, completely spent, passed out with the shower still spraying over her.