Slowly regaining her breath and her composure, she sighed. The other day, she was, to the best of her knowledge, a normal woman with a healthy sex life. In such a short space of time, she had 'devolved' into a dual-sexed freak who had just made love to herself, pumping herself full of the sort of stuff that she did best to avoid. "Clearly that semen had come from somewhere", a voice in the back of her mind surmised - it was about to receive its answer.
As she went to stand, a further noticeable shifting occurred in her groin. Unobscured by underwear, she sat back and observed, worried what was happening...
Alternating waves of numbness and dull-aching spread across her vagina as both sides of her labia seemed to fall saggy and droopy. Then, with an uncomfortable give, two objects 'fell' into either side. She now had a definite pair of testicles to go with her penis, albeit her 'sac' was still smooth (not wrinkly like her male counterparts) and her vagina was still present between them. She could feel a draft in her female sex, caused by the change in shape of her labia.
She stood in front of the mirror - from the front, she looked like a woman with a fairly petite male groin. Turning, with her legs together, she could pass as a completely normal female.
This was going to take some getting used to...