Derrick looked Hebe in the eye. "Is there any limit to what you can do?"
Hebe chuckled amused by the to her dumb question that seemed too obvious to her.
"Of course, I'm not all powerful." she answered not quite completely concealing her mildly condescending tone.
"I can change physique as long as it's possible even if extremely rare, it still has to be possible."
"You can make my age regress and grow my penis, is there any limitation on that?"
She sighed. "I -matured- your penis and of course there's some things that are simply not possible."
"What's the limit, is it for instance possible for me to be 12 and have an even bigger cock?"
She shook her head "You're not the most endowed man to ever life, even now, so obviously, yes, so, you want an even bigger cock?"
""Well, not particularly badly at the moment." Derrick answered. "But out of curiosity how big could you make it?"
"let's see shall we?" Hebe, She swiftly slipped her hand into the water and overwhelmed Derrick by again stroking his penis. He felt a flush of heat again and his penis gained a few more inches. She almost immediately started masturbating him again. His dick felt extremely hard. "And this is how big it could get at your requested age, impressed?" Derrick looked at his cock, it looked quite a bit longer than before. "Practically 11 inches, only slightly thinner despite being a year younger, impressed?" The girl said with a grin. "Like this you're going to become the biggest man alive when you grow up"
"I didn't ask for this." Hebe shrugged. "I'm not omniscient, to be sure of your maximum potential the only way to know is to grow."
Derricks heart was racing his penis was quavering in front of him. "Also, you did ask for this, Derrick, be more clear next time." She said triumphantly. Derrick huffed, he needed to come. "At least jerk me off, then, then make it more normal sized."
Hebe coughed. "I'll fulfil your first request, the second one however, I'd need to make you younger and it would just get as big again later or we can undo this whole thing all together." Derrick gasped. "What?!?" Hebe grabbed his dick "You heard me." She whispered in his ear.