He doesn't have to

Approximately 15 seconds after hitting apply, he heard a distraught scream coming from across the house. Before he could get up, or even put on pants, his little sister practically had kicked his door open as she stormed into the room, clearly freaking out.

"Ohmygodohmygodohmygod," Debra kept repeating frantically, shouting over and over. "I-I was in my room, laying on my bed, thinking about how that dumb cow Katie Belle was flaunting her huge tits again and how it pissed me off, and then I just- It just- I don't even know how-" she jumped from one foot to the other, until Sam's appearance and state of undress stopped her in her tracks. Sam moved, quickly hitting windows+D on his keyboard to minimize the program. He attempted to cover his now much less masculine crotch, his stepsister narrowing her eyes at him.

"What the hell is going on here?! I-I had something happen to me, and it looks like you did too!" She angrily and manically pointed, clearly having seen his smaller cocklet and new feminine appearance, but apparently knew well enough that it was still him.

"W-What are you talking about?" Sam said, feigning ignorance as he struggled to hide his growing erection from behind his hand.

"You know damn well what I'm talking about! You're... different! You look girly, way girlier than usual anyway, even though you were always a fruit to me, big 'brother'," she said, her voice dripping with condescension as her rude personality couldn't help but seep through despite the situation. "And then I- I- It's not important!" she said, blushing furiously while forcing her hands down over her yoga pants.

"Wait, what happened to you?" he inquired, knowing already, but wanting to see the fruits of his 'labor' laid bare before him.

"I-I said it's nothing!" Sam's irate stepsis replied, shifting uncomfortably on the spot as he removed his hand from covering his junk and attempted to reach for her, only for her to jump away. "H-Hey!"

Ignoring her jumps, he attempted to reach for Debra's hands again and again, trying to remove her hands to reveal the prize inside. "And why do you keep covering your crotch? I look more feminine, yeah, but you look just the same, really. The same bratty, annoying little sister you've always bee-"

"I GREW A FUCKING DICK, OKAY?! A HUGE, DISGUSTING, FUCKING COCK! WHAT THE FUCK AM I SUPPOSED TO DO WITH THIS?! I'M FREAKING OUT, AND YOU JUST STAND THERE ACTING LIKE I'M CRAZY! STOP FUCKING SMIRKING, YOU DUMB WHITE BITCH! THIS ISN'T A FUCKING GAME! YOU THINK IT'S FUNNY SEEING ME LIKE THIS?! YOU'RE SUCH A FUCKING FAGGOT! YOU PROBABLY GET OFF ON THIS, DON'T YOU?!!!" she screamed, furiously stamping her foot down on the floor as her face turned beet red, looking on the verge of crying, the anger and pain palpable in her voice, and yet Sam's desire to see it pushed him forward.

"Pffft, haha, yeah right, sis. People don't just grow dicks, Deb, despite whatever's happening to me. You're probably lying and-"

"FINE, IF YOU DON'T BELIEVE ME SO MUCH, PIN DICK, THEN LOOK FOR YOURSELF!" she roared, and with that, she stood up, and promptly pulled down her yoga pants to reveal an absolute monster cock of his design.

The thick, dark length was covered in bulging veins, a pair of huge testicles swaying underneath the angry, bobbing organ as Debra's knuckles tightened in anger and trepidation. It was huge in its own right, but on his stepsister's petite Asian body, it looked positively massive, hanging under its own weight as she stared at him nervously, some actual vulnerability showing.

"Well?!" she said, with much less anger and much more fear in her voice, her voice cracking.