Tae made her way to the counseling meeting and met "that guy" outside. He smiled a little shyly at her, and the two held hands absent-mindedly. He whispered to her, 'I kinda wish we could just fuck here and now,' and she blushed hard, practically feeling her pussy moisten at the thought of him fucking her again.
Once they went inside, things started out pretty boring, as the counselor just explained a bunch of stuff about how the pill worked. But after a while, he moved onto talk which inflamed both their horny minds. "I should warn you, the pill Tae-chan has taken will affect both of you if you have sex again, and will affect both her and any man she sleeps with. She will imprint on him, and become intensely addicted to fucking that man; in turn, he will become addicted to fucking her."
"I think we're getting to that point already," Tae admitted, barely able to look at "that guy".
"Considering the effects of the pill, that is understandable," the counselor said. "You feel like this because imprinting makes human breeding instincts more intense. It has caused you to start ovulating even when pregnant, though you will not have more periods, and once it affects him, it will dramatically increase his sperm count. Once your imprinting takes root further, it will make human gestation advance faster. All of this is necessary to make our people more numerous and spread our culture."
For some reason, hearing all of this and consciously realizing it was turning Tae on- and judging from the tent in his pants, "that guy" felt the same. Noticing this, the counselor asked, "Would you two like some time to yourselves?"
"Please," Tae and "that guy" replied in unison.
Smiling, the counselor left and locked the door. Now Tae found it impossible to hold back, and kissed "that guy" passionately. He kissed back, Tae pulled off his shirt and he pulled off hers, and she moaned with satisfaction as he leaned down and sucked on her breast. He dropped his pants and she unzipped her skirt before pulling off her stockings, and she sat on the table as he started to kiss her. Her heart was racing, faster than it ever had in her life as a boy- she could almost forget she'd ever been an American boy called Ty.
At last she pulled off "that guy"'s boxers to see his firm, seven inch shaft, and she raised her legs so he could pull off her panties. Totally naked, nothing stood in the way of their mating instincts and desire to imprint on one another now. Ty kissed "that guy" and then turned onto her front, her hard nipples rubbing against the clinically cold table in a weirdly exhilarating way.
His cock pushed inside her for the second time in the last 12 hours, and their DNA intertwined as their bodies did. He thrusted his cock into her and she thrusted her hips back, their motions reflexive and instinctive more than conscious. They rutted, grunted and yowled like animals in heat, unable to stop even if they'd wanted to.
Every touch of "that guy"'s body against Tae's felt more intense than any sexual feeling she'd ever experienced, and inside them their bodies prepared to create more and more new offspring. Tae had indeed started to ovulate, at least half a dozen eggs inside her waiting to be fertilized by now, and "that guy"'s balls seemed to almost vibrate as more and more seed formed inside them, so when he came, almost twice as many sperm would be in the semen he shot into Tae.
These changes, and the effects of the pill, drove both of them closer to orgasm, and hearing a loud groan from "that guy" and feeling his seed start to shoot inside her pussy pushed her over the edge. She clung to him, her pussy claiming his cock as her womb was indelibly marked by his seed. Uncountable amounts of energetic sperm swarmed around her ova, and fertilized each and every one.
Both their bodies were rewarded by a huge inrush of hormones affirming their mating urges, and intense love for each other- or at the very least how this mating made them feel.