“Hey, careful! Y-you’re tickling me!” Tessa giggled nervously, adjusting her tiny skirt to try and hide her panties. “Y-you’re gonna make me start milking!” Sure enough, small wet patches were beginning to build in the front of her shirt, soaking through her bra as her nipples began to lactate from the stimulation like a prized dairy cow. “S-seriously, stop! You’re gonna r-ruin this shirt!...”

Terry was a straight-A senior student and science prodigy who had been experimenting with bovine hormones in his free time to try and increase the milk production in dairy cows when he accidentally spilled his concoction all over his body. The changes started manifesting almost instantly: He started shrinking, losing inches off his height as his hair turned long and blonde, covering his face which was becoming softer and cuter by the second. His arms lost muscle definition as his hands become slender and delicate, nails lengthening and becoming soft and supple. His waist pinched in as his hips flared out to accommodate for his womb, his dick dwindling into nothing but a tiny clitoris as the space between his legs rearranged itself into a tight, feminine slit. His legs were next, thighs thickening as his feet became short and slim, then the excess weight he had lost began to pool in his lower body as his ass began to expand into two curvy, tight cheeks that flared out like an Instagram model.

The final touch and the icing on the cake of the transformation was the building heat in his chest. His nipples became highly sensitive against his shirt as they grew out, the mounds underneath filling with thick, creamy milk as he climbed up a bra size every few seconds. Buttons were beginning to fly across the room as his breasts began to fill up, eventually breaking out completely as his bare boobs began to spray milk all over his personal lab equipment, the sexual pleasure of the transformation and his leaking tits bringing him to his first female orgasm as he passed out in pure adult bliss.

Two weeks later Terry (who now went by Tessa) had returned to school and was trying to get back to normal, but things were a lot more difficult than she expected. With her generous assets and short skirt, she was the center of attention throughout the whole school as students (and even teachers) couldn’t help but snatch a glance at the sexy new girl. Worse, even with the J-cup super-absorbent maternity bras she was wearing, the constant lactation meant that if she didn’t empty her full, tender milk-filled breasts every couple hours she would start ruining her uniform, and that was only made worse when her ‘friends’ starting tickling her which always made her milk production ramp up. At least her research had been fruitful: it was found that her breastmilk had the effect of greatly increasing breast growth in women, which meant that every ounce was worth a fortune to her female classmates who wanted ‘a little extra’ up top (the only side effect was high levels of milk production like a pregnant woman). Tessa hoped to use this funding for personal research into reversing her condition, but deep down she kind of liked the money - and the adoration - that came with her new body.

She was curious on what effect the bovine hormones in her milk would have on the male body, and if her calculations were correct, the phrase ‘hung like a bull’ might not be such an exaggeration after all... and with the sexual pleasure the milking sessions was giving her, she was curious about what it would feel like to have her nipples suckled by a handsome stud while he bred her like a cow in heat. For science... of course.