Yeah. I wanna fuck her.

Almost like a squad of entranced fools about to be drained dry by some vampiric monster, I and my four companions stumbled after Dr. Johnson, eager to have any kind of interaction with her. Past the wooden door was a long and shaded hallway, lined with leagues of similar doors, until one such door was open, light streaming out of its opening.

As we all came into her office, what awaited was a typical examination room, the kind I remembered dozens of growing up whenever I went to get a check-up. There was an examination table parallel to the far wall, as well as about three or four plastic chairs. Dr. Johnson herself was sitting in a cushy office chair next to a somewhat sparse desk, head resting on one of her hands and legs crossed, with the same somewhat blank expression as before.

As she said “Now, which of your companions will be receiving the Penile Enhancement? I’m assuming all of them.” we each let out a breath we didn’t even know we had been holding. I started nodding, saying “Y-Yeah, that’s fine.” before remembering Kate hadn’t had any interest in getting a penis. Despite this, I hadn’t heard her say anything to correct me. In fact, I think I heard mutters of “Yeah, gonna dump my load in that hot body...” coming from my magically-aged-up daughter. Heck, everyone was drawn in by Dr. Johnson’s dynamite figure... I assume at least. I was staring only at her too, remember?

Dr. Johnson nodded, continuing “Excellent. Would you like them to make cum of their own genetic material, or someone else’s?” which threw me off a bit. Kinda snapped out of the funk her body had me in, I asked “Excuse me, what was that? Are you saying they could have penises that don’t... make children genetically related to them?” while scratching my head.

Beverly smiled, saying “Ah, so you’re lucid now, that’s acceptable. Perhaps it comes with the territory of being a Mindslaver. Or something besides that. But to answer your question, you can change what their cum is derived from. Normally we generate testes based on the person receiving the penis, but we can start growing testes with different genes if you prefer. As an example of what would result, imagine the circumstances of Terry McGinnis’s birth in the Batman Beyond cartoon, namely that his father had been treated so that the sperm he generated would carry the genes of Bruce Wayne instead of himself. It’s an option that a Master who wants to spread their seed far and wide would be ill-advised to decline.” as she crossed her legs to the other side, showing she wasn’t wearing anything under the lab coat.

I held up a hand as if to say “Whoa, let’s not go too far.” as I replied “Okay, I do want that, but is there an option that lets them... switch? Like, mentally pick which semen to shoot out? Or even shoot out a mix of both?”

This gave Beverly pause, raising an eyebrow as she answered “I... suppose. I’d need to make two sets of testicles grow... or perhaps one of each, including the generation of special nerves that allow for the choosing of which particular ball to blast with...! You’ve made an interesting ask of me, Mr. Doe! It’s an inspired choice...” while slowly getting more enthusiastic as she spoke.

I scratched my head, replying “Aw, thanks. Say, do you think you’d be interested in joining up with us and the rest of my harem? I bet we could use a doctor like you! Even if you, uh, mostly do penis procedures.” while extending out a hand.

She smiled, accepting the handshake. “I suppose I’m only one of an infinity of Buxom Genital Upgrading Specialists. Might be fun to practice in the other multitude of medical fields I studied. And get pregnant with countless babies while I’m at it.” she answered, raising an eyebrow.

Beverly soon broke the handshake and reached into her desk’s drawers, pulling out some kind of odd gun-like device. “But first, your requested Penile Enhancements.” she said, quickly pushing a variety of buttons on a mini-touch-screen attached to the gun, before a tube popped out of the bottom of the handle.

“Now, this isn’t strictly necessary, but if I’m joining your harem I want a proper initiation.” she said, unbuttoning her jacket as she spread her legs, revealing both a breathtaking pussy and a monster of a dick, almost a foot long. Not needing to be told twice, I grinned as I pulled down my shorts, lining myself up with her and penetrating as far deep as I could go. By the time I was balls deep, her eyes had Heart Pupils, she was Immortal and Tireless, and her fertility was through the roof.

Already gasping for breath, I asked “By the way, hah, do you have anything for, hah, sexual stamina? I’m kind of a quicksh-OOOoohh-ot...” not even finishing the sentence before blowing my load inside her. I hardened back up quickly, but it was still a little demoralizing. Beverly chuckled “Hehe, yes, I do. Though it’ll have to wait until after I manage your slaves’, or rather my new harem-mates’ Penile Enhancements. They’re different procedures, you have to understand.” while the tube that popped out of her gun extending to suck up stray ropes of cum as I kept thrusting inside her.

After a few minutes of quasi-cleaning, Beverly’s handheld device beeped three times, making her press more buttons on the display as she said “I’m going to assume you want the testes inside the body, where it’s safer. Don’t worry, they’ll be heat-resistant so that there isn’t a need for holding them in a scrotum.” And, yeah, she was right, it certainly was simpler.

Once I had cum inside her as much as I wanted, I pulled out, shocked to see that my remaining cum had been kept inside of her body, accompanied by the same swelling as that blue-haired girl. Suddenly, though, the bloating lessened, and her body was her original figure. “Don’t worry, it took, I just absorbed the stray semen for both nutrients and easy cleanup.” Beverly assured me, as a syringe tip popped out of her device. One by one, she injected whatever the enhancement was into Kurt, Kate, Alice, and Berta, who I guess had been standing there somewhat catatonically the whole time.

Within moments the four of them shrieked and moaned in pleasure as right before my eyes honest-to-goodness dicks grew from where their clitorises were! It made sense, since a woman’s clit is apparently the closest thing biologically to the head of a man’s penis that they have. I bet their urethras got shifted to their penises too.

“Wow, that’s great! And they can swap load sources as they please?” I asked, waiting for Beverly to prepare whatever it was would help me last longer before cumming. “Yes, there should have been distinct nerves generated. It’ll be odd at first, like trying to move a finger you’ve just grown, but they should get the hang of it in time for their first actual ejaculations.” she said as she injected me with something. I didn’t feel any different, personally, but I trusted her to do the treatment she mentioned.

As she put her device in her coat’s pocket Beverly said “Now, would you say it’s time for us to go?” which made me think. I smirked “Actually, I think it’d be a good idea to test how fertile my slaves’ new dicks are. You have any ideas how we could do that?” as I mentally raised up Kurt, Kate, Alice, and Berta’s Fertilities and Cum Productions up to the max, noting that there were specific sliders for each of their new testicles in my mental menu.

Beverly smirked as well, saying “I do have the ability to ovulate on command and ensure a successful implantation from a past upgrade. Not to mention the pheromones I normally use that you’ve already grown used to. Perhaps they can try and make me a mother to quintuplets?” as my four companions started breathing heavily. Beverly gingerly took off her lab coat, setting it on her desk as she turned back to her latest partners. “Shall we begin?”