"We've finally crossed the line, haven't we?"
"Yeah. But I still can't believe I'm doing this with Chi-kun."
We cuddled on the bed, chatting about all sorts of things. Even though we'd grown up seeing each other all the time, almost like real siblings, we never ran out of things to talk about.
"Himari Nee-chan, why did you decide to have a Genius Gene Child?"
"Hmm… I guess the simplest answer is curiosity? When I first heard about the Genius Gene, I was so fascinated. The idea that you could guarantee giving birth to a genius—that's amazing, right?"
"...Just curiosity? That's all?"
"Well, there are other reasons too, but yeah, mostly curiosity. I've never met a real genius before."
Curiosity might be the strongest driving force for humans. Recipients all have their own circumstances, but I bet a lot of them, like Himari Nee-chan, are mainly motivated by sheer interest.
"Did you know? Professor Niise was actually a Genius Gene Child."
"Wait, what?! No way. Seriously?"
I'd never heard that before—Professor Niise, the discoverer of the Genius Gene and a two-time Nobel Prize winner, was a Genius Gene Child himself?
"By the time the professor started his research, his father had already passed away, and he hadn't inherited the Genius Gene. So he launched this huge search to find a carrier."
"But the odds are one in fifty million. He couldn't have found one, right?"
"Well, actually, he did find one. But the guy was a 93-year-old grandpa—way past the age of having kids. Still, using his genes and the professor's father's, he managed to decode the Genius Gene."
"I had no idea…"
"When I was in middle school, I saw this special about the Genius Gene on TV, and I just knew. They announced that a carrier had already been found, and I was so happy—it meant I had a chance too."
"You never thought I'd be the carrier, huh?"
"Of course not. Honestly, I still can't believe it. That Chi-kun of all people would be the one…"
"Yeah, same. I only found out two months ago."
"Still, I'm glad. Really glad it's you, Chi-kun."
"Thanks, Himari Nee-chan."
"You know how my family runs a tiny business, right? My parents work themselves to the bone from morning till night, but we never get ahead. I should be the one working hard, but… I'm not exactly top-tier. So I thought, if I could have an amazing child, maybe I could give my parents something to dream about… That's another reason I became a Recipient."
"You're really kind, Himari Nee-chan."
"So, Chi-kun… You have to get me pregnant, okay? ♡"
With that, Himari Nee-chan leaned over and kissed me.
Mwah, mwah, smack, smack.
As our tongues tangled, her hand wandered down to my crotch.
"Ah… You're hard again."
"You're pretty bold, Nee-chan. Weren't you a virgin until just now?"
"Shut uuup! ♡"
She guided my stiffened cock to her entrance and sank down in one swift motion. For a second, she winced—but then she took me all the way to the hilt.
"I'm… getting used to it."
"You okay? Don't push yourself too hard."
"...Yeah."
As she spoke, she started rocking her hips—forward, back, side to side—like she was searching for the perfect spot.
"Ahh~ ♡ Right here… This feels kinda good. ♡"
"Let me make you feel even better, Nee-chan."
I thrust up from below.
"Wah—!"
She jolted, shuddering all over.
"Here we go."
Squelch, squelch, squelch, squelch, splurt!
I matched her rhythm, driving into her, adjusting the angle to hit just the right spot.
Slap, slap, slap, slap, smack!
"Chi-kun… Hold my hand."
I laced my fingers through hers, gripping tight.
"I-I'm gonna… move too."
With that, she planted her feet and started bouncing up and down.
Slap slap slap slap slap slap slap slap slap slap slap slap slap!
The rhythmic smack of flesh was hard to believe coming from someone who'd been a virgin minutes ago.
"How is it? Feels good, Nee-chan?"
"Y-Yeah… It's… getting better… Ah, ahh, too good… I'm gonna lose it. Ah, ahh, no, it's too much… ♡"
Awakened to pleasure, she rode me desperately. At this rate, I was gonna—
"Ah, ahh, no—I'm—I'm gonna—again—that feeling—it's coming—ahh—!"
Her movements grew even wilder. And then—
"Ah—I'm—I'm—ahh, ahhh, ah—AHH!!"
Her insides clenched around me. I couldn't hold back anymore.
Splurt, splurt, splurt, splurt!
"Ahhh… So good… ♡"
She collapsed onto me, nuzzling her face against my chest with a happy sigh. Her way of showing affection was… unique.
"I had no idea sex could feel this amazing. Thank you, Chi-kun."
We kissed again, tongues entwined.
"So, kid. How was it, doing it with the girl next door?"
"Ohno-san, you're evil. I was so shocked."
"Rules are rules—Recipients aren't revealed until the last moment. Still, damn, you really out here living every guy's dream, huh? Bet you're thrilled."
"Of course I am. Seriously. And, Ohno-san, your advice really helped. Thanks."
"Glad to hear it. But listen—I'm putting my foot down here. No private sex with Himari Nee-chan, got it?"
"I know, I know. Punishment if I ejaculate outside of insemination days, right?"
"Damn straight. We'll make you regret even thinking about getting hard."
Why does this guy always have to threaten me? I'd obey even if he asked nicely…