The tingling increased as I got more curious as to what would happen to me. After a few seconds the feeling seemed to center around my chest and groin. I took the tingling around my chest as an indication that Rachel's dad would be getting what she wanted, and sure enough, as soon as I had finished my thought the tingling started to change into a soft pulsing.
The rhythm was perfectly in synch with my heartbeat, and as I got more excited and my heart started beating faster, so did the pulsing increase. Each pulse felt better than the last, and I felt my dick become almost painfully hard, straining against my jeans. The pulsing in my crotch added to the pleasure. My pants felt as though they were getting tighter with every heartbeat and I suddenly realized that they were. I was getting bigger, or at least, my dick was getting bigger. The pulsing had become even more pronounced, and I groaned slightly as the pleasure kept increasing. It was as if someone had hooked my cock and balls up to a small air pump, slowly inflating with each pulse, each throb, and nothing showed any signs of stopping.
I suddenly moved my attention back to my chest, which I had almost completely forgotten about. I gasped in shock as I laid my eyes on it. I could clearly (VERY clearly) see my nipples poke out through my shirt. They didn't even look like my nipples anymore, they looked like they belonged to a very well-endowed woman somehwere very cold. I brought my hand up to touch them, groping my still-growing crotch with the other. They had to be at least an inch and a quarter inch long, not to mention their thickness. I shivered in pleasure as I gently squeezed it through the fabric of my shirt.
A strange smell entered my nose, and I suddenly became aware of how moist my pants felt. I looked at my crotch and saw a fairly substantial damp spot on my jeans. I had to be leaking pre-cum like crazy. The fact that I was extremely aroused didn't surprise me in the slightest because I was well-aware of it. What surprised me was the sheer volume of liquid I seemed to be leaking, and if that wasn't enough, there was a titanic bulge in my pants. I became aware of how uncomfortable my pants were actually becoming. In fact, they were becoming almost painfully tight.
I struggled to remove my jeans, but unbuttoning had become next to impossible because they were stretched so tight. I remembered the ring, and quickly wished the button on my jeans gone. Almost immediately after the button had vanished, the zipper practically burst open, revealing my enormous bulge. I quickly took my pants off in their entirety, and my cock, now liberated from its denim prison, proceeded to tear out of my boxers. My eyes went wide as I realized that I wasn't looking at a human penis, but instead a bull's sheath with two softball-sized balls swinging beneath it and an at least seventeen-inch semi-erect red member hanging out, dripping pre-cum on the floor.
I looked around, noticing that nobody was paying attention to me apart from Rachel's dad, who just giggled. The milk's "normalising" effect seemed to be holding up quite nicely. Good, otherwise this would have been quite embarrassing.
The strange smell became stronger, and I realized that they were pheromones of some sort. Furthermore, now that my pants were no longer holding them back, the very air I was inhaling made me hornier than I already was with each breath. I grabbed hold of my still-growing member, now at eighteen inches at least, and I started stroking until it was completely hard. It was almost two feet long, stopping somwhere around my chest. I began to furiously stroke it, each stroke releasing more pre-cum and with that, more pheromones, increasing my arousal. The smell seemed to be affecting Rachel's dad as well, as I saw her beginning to masturbate vigorously.
My chest, in the meantime, had continued swelling. My nipples were now some two inches long and extremely thick and sensitive. They were, however, now dwarfed by my enormous breasts. They had to be at least the same size as Rachel's dad's, and the wet spots around my nipples betrayed the fact that I had begun to lactate. More shocking than that, though, was the other pair of breasts that had begun growing under the original pair. I released one hand from my monstrous shaft and brought it up to squeeze one of my new nipples. A jolt of pleasure ran through me, causing my t-shirt to darken around the new set of breasts as they started to also excrete milk. I squeezed again, releasing my milk and causing my throbbing cock to squirt out a small stream of pre-cum.
A dull ache seized my face and lower spine as my skull rearranged itself to become a very feminine blend between bovine and human. I gasped as the pressure in my spine released, causing a cow's tail to spring out.
My fingernails darkened and my hands became more feminine, and I groaned in discomfort as my feet reformed into hooves.
My shirt, finally, gave up its struggle against my titanic breasts and split down the middle, exposing my huge, yet very firm breasts. I tingled all over as fur grew over my body in a very fetching, random black-and-white pattern. My ears tickled as they elongated and changed shape, become very cute and bovine.
My torso slimmed, and my body adopted more feminine curves, while at the same time become more muscular and better toned. I grew slightly in height, stopping at a beautiful six feet and six inches tall.
The final change was on its way. I felt my insides rearrange, and I became dizzy. I sat down on a chair and felt beneath my pendulous sack, only to find a patch of skin that was becoming increasingly tender and sensitive.
Rachel's dad couldn't control herself anymore and stopped masturbating. She walked over to me and dropped on her knees, similtaneously prying my hands away from my shaft. She licked it up and down, toying with the base of my sheath and sucked up all of the pre-cum. Then she gently took it in her mouth, before suddenly engorging it completely.
At that moment I lost all sense of reason and started squeezing my nipples furiously as Rachel's dad sucked my huge cock and played with the sensitive patch of skin. My eyes widened and I screamed with pleasure as the skin finally gave way to form my new vagina. Rachel's dad plunged her whole fist inside, moving in and out with furious strokes while seemingly attempting to devour my pulsating rod.
I couldn't hold back any longer, and I came in her mouth. My nipples started similtaneously spraying milk and my vagina released its milk as well.
Cum was streaming out of Rachel's dad's mouth and onto my balls and into my pussy as she struggled to swallow it all. The orgasm was incredible, unlike anything I had every felt before, and I soon lost consciousness.
Minutes later I awoke, Rachel's dad still lapping up the excess cum I was covered in.
I had become an anthropomorphic hermaphrodite cow.