Megan and Will went at it like never before. The vial Will had taken was starting to take effect and Will could feel it. Megan's vial continued to take shape.
"Ow, ow ow." Megan yelped.
Will stopped nibbling her ear lobe. "Was I biting too hard?"
"No, my bra clasp was pinching a nerve."
"Speaking of bras, how are these babies holding up?" Will grabbed Megan's left tit. He could feel the warmth through the bra. He could even see she was erect. He could also tell the bra was definitely too small.
"Ohh Will." Megan moaned. "Take it off."
Will needed no further encouragement. In no time, Megan's growing tits were free of imprisonment. They sprang forward as the pressure was released.
"You're normally a C-cup," Will said as he read 34C on the bra tag.
"Yeah, so?" Megan asked.
"I'm guessing that you are more like a D now babe. Thats quite some growth."
Megan cupped her boobs in her hands. "They feel heavy, huge, and warm." She squeezed them and was surprised to see a white fluid leak out of her left boob.
"WILL! Do you see that?"
"Yes. Don't you have to be pregnant to have breast milk?"
"Will, its the vial I took. This is the interesting event the clerk was talking about. I've always wanted to be able to be suckled during our sex."
Will didn't let it go to waste either. Megan soon felt his lips around her larger nipple. Once Will got the rhythm down, she could feel milk flow from her tit.
"Oh Will, you have no idea how good this feels."
Soon after, Will had his cock up her vagina and was letting loose. He was amazed though that he was still able to go. Usually, he had the let down after cumming, but the vial kept him going.
Little did each of them know that the two vials were mixing in each of their bodies. Will got some of Megan's chemical through her milk and Megan got Will's through his cum. Neither of them realized what this held in store for them.