"Both, I guess. This is all stupid anyway, and it isn't even real!" Jen said. Her anxiety was growing. Was it real?
Kyle laughed on the other end, as if that was what he wanted to hear. "Good, bitch, because you're about to become one. For your transformation, your arms and legs will turn into the limbs of a dog. You'll also grow a tail, and 6 more boobs down your torso. Your face will push out into a muzzle, and you'll grow dog ears, too. Speak now or forever hold your peace, since you won't be able to talk after your transformation is over."
"That's sick, Kyle! What the fuck is wrong with you!" Jen interrupted.
"What's wrong with me? I'm not the crazy, mean bitch that thought pantsing someone in the middle of a *high* school was a cool prank! You're just getting what you deserve. Now, for the rest of your transformation. You'll grow six more boobs, but all of them will be huge. I'm talking, dragging on the ground, too big for you to walk comfortably with on your dog legs huge. Beachball sized at least. Your legs will press into them whenever you take a step, so get ready to be barely mobile." He heard her disgust through the phone at his perverted curse.
"I'm not done! Funny, really, because the final part of your transformation will make it so you aren't a bitch at all, because you'll grow a massive dog cock. It'll unsheathe itself directly between your tits, causing you to titfuck the back few rows of your boobs. Haha, you really think that's gross, don't you? For your dare, you'll act like a dog. You'll still be you, but you'll act like a dog, a pet. In fact, the first person you see at school, you'll become their pet. They will think you've been their pet since childhood, and everyone will see it as normal. They will still think you're a person, treating you like a combination of girl-with-massive-boobs and a dog. You'll protect them, play with them, and love them. However, you'll also be permanently horny, and very aggressive. Attacking, clawing, and biting people who you think looked at your owner wrong. That sort of thing. See you at school, bitch!"
Jen was too in shock to turn the phone off. It clicked as Kyle hung up, but she stood there, frozen. What a fucking freak, going off like that at her, about his deepest fantasies. Get a hold of yourself, you weirdo, she thought. Besides, the curse isn't even real. None of it's real. Why did her arms and legs itch all of a sudden?
Jen fell as her legs cramped. She grimaced as she felt them shift, her arms feeling like they had turned to putty. Her skin burned as fur grew in, and her hands and feet stretched out into the digitigrade paws of a dog. Her vision blurred as her face extended out, becoming a muzzle, and her ears shifted upwards, turning to every new sound she heard. Her chest ached as it expanded out. She looked down, intimidated by her rapidly expanding chest as it filled her vision, her boobs growing to the size of overinflated beachballs. They weren't beachball-like in appearance, filled with enough fat and milk to make a cow blush, but they sure gave them a run for their money in terms of size. Jen winced as 6 more equally huge boobs grew in down her chest, competing for the limited space of her athletic torso. They pilled up on top of each other, her first pair sitting so high that her muzzle rested between them. She laid back on her bed, feeling them surge back, covering her face. She tried to paw at them to get them off, but her new dog forelegs didn't have the range of movement.
As she tried to get her heavy tits off of her face, she froze. She felt her vagina turn inside out, becoming a sheath that extended well into the space of her 4th row of tits. Her ovaries shifted, and she felt them fall into her new sack. Her tail began to wag and she started to pant as she became unbelievably horny. Her cock loosened from its sheath, and she felt it brush between her soft boobs, causing her torso to buck. All her thoughts of revenge, of how perverted Kyle was were wiped from her memory, replaced by an intense urge to fuck any dog or girl she could find. She also knew she needed to protect her owner, whoever that was. She'd remember when she saw them, she knew that.
As she laid there, the pleasure building in her rock-hard cock as she humped between her own boobs, she realized she had to get to school. That's where her owner was, and she was a good pet. Loyal, protecting, they needed protecting! She flopped over onto her side, her boobs splayed out before her, before she managed to shift onto her legs. She stood on her bed, barely able to get her paws to touch her mattress around the sheer mass of her overwhelming boobmeat. Try as she might, she couldn't jump down from the bed. She ended up falling, wincing as she landed on her 8 sensitive nipples, however, she was cushioned otherwise by her immense breasts. She stood up, amazed at how heavy they were. She tried stepping forward, and felt them drag underneath her. Each step was labored, more of a waddle to get around their mass. At this rate, it would be a long time until she was at school, but an thought in the back of her mind told her her owner needed her protection now!! No time to waste waddling, no excuses!!! Now now now!!! So she tried to run, tripping over her tits, and settled for a speed-waddle to school.
Edit: For context, I'm imagining her boobs like the animation 'Hyper Pushups' by draemam on Furaffinity except 8 instead of 2