Author note: Tony is Charlotte's brother. He will transform into her and be called "Fake Charlotte" they are the same person. I will be using the pronoun she/her, and the word sisters to describe their relationship.
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Tony transformed into his sister, Charlotte. Tony, Fake Charlotte, was a woman once again. She adjusted her white tank top to be low cut to catch Mark's eye, and pulled a tennis skirt high enough her panties would show when she bent over.
Before going to the front door, she secretly set up a camera in the living room. She linked it to a live stream on her sisters social media account and titled it 'I've been a virgin too long, I can't stand it.'
The doorbell rang again, and Fake Charlotte took a deep breath. She opened the door to Mark and gave him a big hug, squishing her breasts tight against him. "Go sit in the living room, I'll bring you a beer," she said, giving him a kiss. He seemed a little surprised, but didn't question her good mood.
While her sister was chatting up her boyfriend, the real Charlotte struggled wildly against her bindings, but it was impossible to move more than an inch. To get a little dignity she put her knees together, but it was barely enough to cover her pussy, and the blond pubes sprouting out on display.
Under the pretence of getting Mark a beer, Fake Charlotte went up to torment her sister. She looked exactly like Charlotte, "your boyfriend will be up here later for his fuck session, but I need to make sure you are nice and ready first."
Hearing this in her own voice threw her. What was her brother going to do with her boyfriend? Why was he pretending to be her? What did he mean by 'get her ready first'? Getting worried, Charlotte started screaming to Mark for help, but in the soundproof room screaming did nothing.
Getting aroused by her desperation, Fake Charlotte, reached down to spread her sisters legs and exposed her virgin pussy. Using a soft, tender touch, she began to finger it. Even though it felt good, the disgust she felt from her own family member forcing her fingers inside was stronger. Her hairs stood on end, and she closed her eyes as tight as possible while tears ran down her cheek.
The feeling started to get more and more intense. Charlotte knew if this kept up she would orgasm, yet she still wanted him to stop. She couldn't help but focus on the bizarre feeling of her pussy getting bigger, and firmer as Fake Charlotte transformed it into something new. It had already grown by several inches, and didn't feel wet at all. Instead, it was hard and pulsing inside. Charlotte's sister was pumping it now, making it grow larger and larger until it eventually started pressing against her breasts.
Charlotte opened her eyes to take a look at what was going on. Instead of her vagina, she saw a 20 inch cock stretching up between her legs and into her tits. Her eyes bulged as she realized what her brother had done to her innocent feminine body. She tried even harder not to cum as the tip of her cock bounced between her soft breasts, and her sister worked the shaft. The long slow strokes were amazing. With each pump Fake Charlotte put more nerves inside her new cock making it impossible not to cum.
She clenched her ass hard trying to stop cum from firing into her soft warm welcoming tits. The harder she clenched, the more her cock throbbed "c'mon little sis, there is no need to resist. I can see the perverse look on your face, just let it all out." Fake Charlotte was expertly using her small female hands to switch between gentle caressing and firm strokes. When she was close to the edge Fake Charlotte pressed her tits against her sisters moving up and down. It was a double tit fuck against the tip of her cock. It was impossible to resist. Charlotte was going to cum!
Warm white cum bubbled slowly up her shaft. It oozed up out of her bulbous cock head and into their tits. "I'm cumming!" Charlotte screamed. "Oh god, I'm actually cumming." Horrified and relieved at the same time, she watched as it slowly formed a small pool inside the identical pair of breasts tit fucking the monstrous cock bursting forth between her legs.
As the feeling slowly left her cock, it began to shrivel, followed by a thick white trail of cum. Watching her sister pathetically sit there in post orgasm shame, Fake Charlotte puller her sisters head into her cleavage and forced it onto her face, and into her mouth.
"One orgasm isn't enough, I need you to be truly addicted" she said to her sister.
She rubbed the base of her sister's cock making it feel good again. Two fist sized balls were forming at the bottom, and Charlotte was getting hard again. "Please turn me back into a woman," she begged.
"You won't be able to enjoy what I do to your boyfriend as a woman though," her brother said, smiling.
"What are you going to do to him?"
"I'm just going to make him compatible with your new body," Fake Charlotte said making and picking up a soporific beer in one hand, and putting it gently on the bed.
