A Sister

"So...that's what's happening to me," Johnny Storm said. Now that Sue Storm knew to look for it, she could almost see the more androgynous aspects of her sibling's face—eyelashes a bit longer, jaw a bit narrower. No facial feminization surgery, but something more primal. The Human Torch's own body was working against him.

Her, Sue thought to herself as she stepped forward and hugged Johnny to her chest. In her mind, Johnny was already her sister. The silly girl just didn't know it yet.

Which is why she'd continued to slip more of Porkum's jizz into Johnny's food and drink.

"Oh, Johnny," the Invisible Woman said. "It's okay. We'll get through this together. We're family, after all."

Hour by hour, day by day, week by week, Johnny Storm's body changed itself. Sue could see how awkwardly Johnny fit into their Fantastic Four costume now, the skin-tight clothing meant for a trim, muscular young man oddly ill-fitting on who Johnny was becoming. Even in civilian clothes, Johnny now favored loose hoodies and sweat pants that hid their body.

Yet Sue had been sneaking into Johnny and Reed's daily examinations. So far, Mister Fantastic had only been able to document the changes.

"I'm still finding traces of that odd mutagen in your system," Reed said with a frown. "Have you been eating anything unusual?"

"I haven't left the Baxter Building," Johnny said.

The Human Torch lay naked on the exam table. The breasts were much more developed now, not just little flabby masses but like a pubescent young woman's, the nipples particularly large and puffy. Much of Johnny's body hair had gone, and the head hair was longer and finer, falling almost to their chin. The most impressive change had been to Johnny's hips, buttocks, and thighs, which had filled out and spread.

And between those legs...

Johnny Storm's cock had shriveled to a nub. The testicles had shrunk as well, which made the scrotum look unaccountably shrunken and wrinkled.

"I'll need another ejaculate sample," Reed said as he handed Johnny a small plastic cup. "You know the routine."

"I can't fill it," Johnny said despondently as they took the cup. Reed didn't meet Johnny's gaze.

"Just do your best. I'll...I'll give you some privacy."

Sue's lip curled. Johnny turned onto their side on the table. There was a large high-definition screen there, a remote control. With the press of a button, a list of pornographic films flicked onto the screen. The Invisible Woman's nostrils flared. She had been waiting for this. It had been why she had continued to sneak into these sessions.

As Johnny's finger went to press a button, Sue let an invisible finger press another. The screen shifted...and on the screen a blonde transgender woman appeared. A montage played of her getting plowed from behind, a thick cock in her tanned ass as the titles rolled. Johnny paused, hesitated...and then with two fingers, began to jerk their microcock, blue eyes focused on the screen.

The Invisible Woman smiled as she watched, her own pussy clenched as she squirmed in place. She could barely repress a shudder of pleasure as Johnny reached back and pressed a spit-slick finger against the tight little asshole. The Human Torch moaned softly in time with the actress on the screen as a watery fluid leaked out of their cocklet into the cup.

Little by little, Johnny was becoming a woman mentally as well as physically. She just didn't know it yet.

"How is it going?" Sue asked, as her husband stood hunched over a microscope.

Reed looked up and sighed. "Johnny's latest ejaculation. No trace of sperm. His gonads are in the process of transforming into ovaries. It's fascinating, really. Macro-scale changes like this aren't natural for homo sapiens.

If only I knew the cause! This mutagen is the product of a completely divergent evolutionary line. Incredibly aggressive, specifically targeted against sexual characteristics at cellular and genetic levels."

Sue studied his shoulders, the tenseness of his muscles. "It has the potential to revolutionize gender-affirming care...but if I can't figure out a way to stop it, for Johnny's sake..."

He let the sentence trail off. His head slumped between his shoulders.

"I think—we might need to talk to Johnny about transitioning. Socially, as well as physically," Sue said, as she stepped forward and laid her hands on his shoulders. "I was thinking of taking Johnny to be fitted for a proper bra."

Reed frowned. "I don't think he'd appreciate that. He's already stressed from the changes in his body—"

"Why don't we let Johnny decide that?" Sue said, as her thumbs began to dig softly into his tense muscles, fingertips massaged his neck. "If nothing else, having some clothes that fit might make Johnny a little more comfortable."

Mister Fantastic frowned, but then he leaned back.

"Maybe," he said. "I suppose you could ask."