Mary, now Mark, had the perfect idea. He didn't know if it would even work, but he had to try. He ran back to the kitchen where he had left the box of vials and brought them back into the bedroom. Setting them on the bed, he plucked the refilled male vial from it's spot in the box again. Mark wondered exactly what would happen if a male drank from the male vial, perhaps nothing, but perhaps he would become more male. It seemed to make sense. So he uncorked the bottle and swallowed down the contents. As a familiar tingle began to pass over his body he placed it back where it belonged, once more watching it fill up with the blue liquid.
Mark turned towards the mirror, waiting for the changes to start. He didn't have to wait long. All his muscles began to spasm, flexing and relaxing, each time they did so they grew a little bit bigger His six pack became an eight pack, his pecs became slabs of hard muscle. His arms swelled with muscle, as he flexed for himself in the mirror, his biceps bulged into tall peaks, already twice the size of what they were mere moments ago. His legs seemed to be following suit, his thighs pushing apart as they grew with muscle, even his calves becoming thicker and heavier.
His bones stretched out and thickened, becoming a heavy frame to support all the extra muscle. A few more inches in height, as well as broader shoulders and a heavier chest. Even his jaw was stronger, with a broad chin and a heavy brow.
His cock gave a twitch, once more going fully erect to it's seven inches, then pushing out further, going to eight, then nine, then ten inches, thick enough around that he could barely even get his large hands to completely surround it. His balls hung heavier, lemon sized balls dangling between his muscular thighs.
Next the hair all over his body began to thicken. Dark and curly, his shins and forearms were forests of hair in mere seconds, sparser but still significant hair covered his thighs and met up with his thickening pubic bush. The hair on his stomach spread outwards, his heavily defined abs becoming obscured beneath a curled pelt of dark hair. His chest hair grew similarly, covering the broad expanse of his pecs, leaving only his to nipples as points of bare flesh among the heavy fur of his chest. His beard grew in thicker as well, soon he was sporting a full beard on his lantern jaw.
Mark flexed once more in front of the mirror, going over the poses he had seen the body builders do so often at the gym, where as a woman he had only done some light weights. But now she felt so powerful, heavy, but powerful. No wonder those guys spent so much time on the weights, it was amazing how it felt, the feeling of strength in his muscles.
He rubbed along his jaw, leaning in closer for a better look at his face in the mirror. The beard was interesting, but he wanted to do something with it. He moved into the bathroom, digging out one of the razors he had been using to shave his legs as a woman. Carefully he began to trim the beard, then shave, sculpting it into a clean goatee and long side burns. Even looking at himself in the bathroom mirror was turning him on again. It seemed that while his body changed, his mind stayed somewhat the same. But now instead of making love to men the way he had before, he wanted to plow them cock-eyed, feel what it was like to drive a rigid cock into someone's tight ass. At the thought he could help but to jack himself off again, spraying twice the load as before all over the bathroom wall, it felt like buckets came shooting out of him as the orgasm wracked his body. It left him panting, gripping the side of the sink as he regained his breath.
Mark ran his hands through the heavy pelt of fur on his chest and stomach, considering what he should do now..