"I can't believe I lost my virginity that way, and to you of all people." Jen's brother sighed, remaining silent for a bit as he rubs Jen's thigh. She was too shocked to even knock his hand away. However, he smiled, having concluded what to do here. "Not to mention that you really enjoyed that, didn't you?" He questioned, to which Jen gave a fierce no. The curse triggered again, as her breasts swelled to P cup this time, with her hips, ass and thighs inflating to thick sizes as well. Surprisingly, Jen also found her height increasing too, reaching to almost 8 feet tall. Her lips plumped up in size, looking almost comical, to become DSLs on her face. "What's happening?" She cried, realizing that these changes mean that her brother must've thought of new ways for her to pleasure him. Having become a curvy amazon, Jen picks up her brother and brings him to the hall closet, whereupon the next part of her brother's desires kicks in. He's already stripped nude by now, as Jen pulls down a new pack of hiking rope from a shelf. Pushing her brother to the floor, so that she could bend down to push his dick back into her shaven pussy, he wraps his arms and legs around her waist and torso, to effectively be carried.
Confused as to what the combination of the curse and her brother's sexual wishes are making her body do, Jen finds her body unraveling the rope, and start tying it around her and her brother's bodies in some kind of super complex rope bondage. Her body ties the rope tightly, finishing by tying the ends into abstract knots, around her back. Having not seen how the knots were made, it would be very difficult for her to ever undo them. Now that the setup is complete, her body, with her brother tied to her front with their genitals deeply connected, pushes him against the wall. Her manicured hands grab his hips, and she starts humping him like mad. Her vaginal muscles are desperate, nearly crushing his dick with every slick thrust. With the way he was tied to his amazonian sister, Jen's brother had his face between her humongous tits. Within the sweaty cleavage, he licks and sucks the sides of her breasts, pleasuring her immensely.
"Oh god!" Jen moaned from her plump lips, licking them out of lust and ecstasy; she found they were additionally very sensitive as a new erogenous zone. She rubbed her nipples with one hand as she continued fucking her brother. "I want this to stop!" She exclaimed, which apparently was a lie, as her body sped up it's thrusting even further. With such her, the tip of her brother's dick reached so deep into her pussy, it kept hitting against her cervix. "Not agai-" Jen shouted, as her pussy constricted around his dick, as she released a stream of fluids, indicating her climax. Her brother also climaxed, releasing a load even bigger than the first one, directly into Jen's womb.
Laying on the floor on her back, Jen panted as her brother still lay atop her with his rod in her cunt. With the two tied up, it's not coming back out anytime soon. "What have you done?" She asked her brother, who she had to slightly part her breasts to be able to hear. "It's simple," he began. "The curse makes it so that your body becomes and does whatever to sate the desires of the one you're about to screw. And then, so long as the two of you are having sex, the changes remain. With this, we will always have sex, and you'll always stay this freaking hot amazon. You're my woman now; I'll be the only one you'll ever have sex with, and only my cum will ever go in your holes from now on. Do you love that idea?" he mischievously stated, lightly thrusting against Jen to keep her pussy in the mood.
"N-no, I hate that idea and don't want this situation to stay permanent." This turned out to be another subconscious lie, as Jen started crashing her hips against her brother's once again. "Don't forget, Jen, you also have to go to school, or else you'll be late; don't want to ruin that perfect attendance, right?" He continued, knowing that Jen was all his from now on. Thanks to the specifics of the curse, Jen will never have sex with anyone else ever again, since she's always doing it with her brother. Being seen at school like this was not what she wanted in the slightest, but she might not have any choice.