Mary had an idea. "Heh, my boyfriend's always belittling women so why not turn into the so-called "better gender"...and put him in my place." She took out the Gender vial and drank it, claiming "if it works, this is going to be good...if not, just as well." Soon, the effects of the potion began, and Mary saw fine body hair developing all over, her head hair shortening a lot. She felt muscles rippling beneath her skin, quickly making an end to her petite, fine-contoured body as she even gained a bit of height. Her shirt and bra started to droop a bit as at the same time her breasts completely receded into her body, leaving nothing but small nipples, and now it was time for the biggest change...she saw a bulge in her pants growing until she was nearly screaming at the pain of wearing way too tight underwear and pants, and with that she quickly unbuttoned her pants and let down her underwear, quickly revealing her new schlong and the nutsack that dangled beneath it. She gave it a poke and it wobbled back and forth a bit, giving Mary completely new feelings that she didn't expect. "Jeez, how can guys live with these things?", Mary, now Mark thought to himself. He thought to himself that if it could change Mary into this...it would be interesting to see what the potion could do for Mary's boyfriend. But first, he'd put on some new clothes as female clothing hardly fit him anymore, already have a bit of trouble removing the clothing designed for such a delicate figure.