Karen felt her panties change into something like a men's briefs and her clitoris grow out into a penis as her new testicles dropped. She shifted uncomfortably from the new presence between her legs, doubly so since her pants were still changing cut to have room for it.
Jon was staring at her crotch, his own penis hard as the wishing rock.
"Looks like you're in the male part of your cycle" said Jon.
Karen stared at him, still shocked at what he had done. Jon was clearly distracted by the changes, and she was now free to move again so she made a quick grab and got the stone from Jon.
"Huh!"
"My turn Jon-boy! I wish that you would stay silent and not try to touch me or the stone until I finish wishing."
Jon stared at her, slightly frighted.
She thought for a few minutes about what she should do, she couldn't reverse what Jon had done.
"Reverse..." she thought, and an idea occurred to her, and after a little more thought she wished.
"I wish that men had a genital cycle too, and that it would synchronize to women who they found attractive and spend a lot of time with, and do so in such a way that it will almost always synchronize people who are in a relationship to be on opposite parts of their cycles."
Almost immediately after she finished speaking Jon's chest started changing as a pair of breasts grew on it, and the erection faded from his pants as his penis changed into a vagina, since he and Karen were on synchronized schedules, both being single and finding each other attractive while spending lots of time together. The breasts Jon wound up with weren't too large, but they weren't small either. No other parts of his body changed, he was still masculine. As he sat there in confusion his clothes started changing to match his form, his underwear changed to panties and a bra appeared under his shirt, the cut of his shirt changed to have some room for breasts, but it was tight around his.
Jon looked down at his chest and then up at Karen.
"Why do I have these?"
"I don't know, I wish we knew why Jon has breasts."
The knowledge flooded them.
Men now had breasts because on the female part of their cycle they could get pregnant and so they had breasts too, and as it turned out men on average had quite modest breasts, Jon's were actually huge for a man.
At this point Karen realized that she found Jon's new chest slightly distracting, she also realized that women's preferences had changed, they now liked men's breasts, but she also realized she was slightly unusual in that she liked her men on the busty side (like Jon).
Her attraction to Jon and the way his shirt, because it was a men's cut, didn't have enough room for his breasts was giving her a slight hard on.
Neither of them were virgins, but the relationships had ended some time ago and both Jon and Karen were feeling a little lonely for something other than friendship.
"Oh wow, that feels different... Oh jeese Jon just had a massive hard on, I wonder if that means he's all wet now." This line of thought got her a little harder. "I wonder what it's like from this side of things."
Karyn, knowing that there had been a mutual attraction between them made a suggestion.
"Jon-boy, you're an asshole for springing this situation on the world, but I still love you, and well..." she hesitated, working up the courage to say the next part. "I wanna know how sex feels with this new equipment, and we both know that our cycles are synced, you wanna, well... ?" She trailed off.
