Naruto suddenly placed both his hands on Boruto and Boruto, in surprise, began to say "What are you..." but trailed of as his father's warm and powerful chakra began coursing through his body. The young man's mind was then overwhelmed with pleasure as he began to grow and expand in all directions. Before long he could hear the sounds of tearing fabric and himself moaning, but his mind focused only on this carnal bliss. Only twenty seconds had passed and already he'd outgrown his father by a wide margin, and he continued to ascend, vaguely aware of the feeling of his erected cock slapping into his father's slack jaw, as arrived and easily surpassed double the Hokage's height with the energy showing no signs of abating.
Naruto was more than a little surprised at how well his son's body responded to the small amount of chakra he'd provided, rubbing his jaw he simply watched as his, now fully nude, progeny began to idly stroke himself with one hand and rub his tight muscles with the other. After thirty seconds of stroking, moaning, and growing Boruto had easily quadrupled in size when he sat on the forest floor and lay back to stroke his member with both hands. Now standing between his son's massive growing legs Naruto decided it'd be safer to jump atop his offspring as the limbs beside him and testicles before him were an ever encroaching threat to his position.
Boruto barely felt the impact of his father landing on his torso as his mind demanded one thing and one thing only release, immediate and imminent release. Continuing to pump himself with a nigh frightening ferocity he continued his expanse easily doubling in size once more as his body, even laying down, far surpassed the tree line. Unfettered by the fact his father now stood amongst his six tight abdominal muscles he gained once more in speed as a final growth spurt pushed him over the edge, and with a deafening roar of climax the boy shot load after load high into the night air all to come down and paint him with his seed.
Now basking in the afterglow a two-hundred foot tall Boruto panted heavily as a cum stained Hokage appeared before him, standing on his pec "Understand why it's such a big secret now?" he asked.
"Definitely," Boruto replied, still somewhat short of breath. "But people are gonna freak out when they see me," he pointed out.
"Well the effects are only temporary," Naruto explained, to his son's not-so-secret chagrin, "However that was only supposed to be enough to make you two feet taller not two-hundred feet so who knows just exactly how long this will last."
"Wait if it's such a big secret, how come you had an idea how big I'd get? Even if you were wrong," the giant asked his father.
"Well, I have tested it some," Naruto explained, "I would go out into The Forest of Death and experiment on the bugs and some of my clones."
"I guess that makes sense," Boruto admitted, considering the whole of the situation. Soon though, despite his orgasm from moments earlier, he began to feel his cock stirring anew as he looked at his father, this tiny being coated in his seed was capable of this and, presumably, so much more. The possibilities alone were enough to send his hormones back into a tizzy.
Noticing that behind him his son's monolith was rising Naruto said "Really? I know eighteen year olds are horny, but gimme a break."
"I can't help it," Boruto said indignantly, "It's just so damn hot..."
"Hey don't swear," Naruto chastened, involuntarily entering "dad mode."
"Oh come on, I'm huge, naked, and I jizzed on you, but I can't fucking swear?" Boruto pointed out.
"That's two, but I guess I can see your point..." Naruto conceded, shedding his now soaked layers of clothing.
Standing now only in his boxers, with the dorky little ramen cups on them, Boruto couldn't help but feel something within him stir as he looked upon his nearly nude father, "...You know dad...it'd be pretty cool if...