"Like do you think that...you could maybe...try it on me?" Boruto asked desperately trying, and failing, not to betray his nervous excitement.
Naruto looked a bit surprised in response to his son's request "Um, I guess I can try it," Naruto said, accompanied by his instinctive parental nervousness, "But are you sure? I mean I've never done this to anyone but myself."
"I'm sure!" Boruto said, excitedly looking into his giant father's eyes. "Besides think how cool it'd be if we were both so...so...*ahem*...cool..." he clumsily fumbled to keep himself from saying hot, as he shifted his legs for a second time to try and hide just how cool he thought this whole situation was, hoping his father didn't simply feel his son's excitement on his snout.
"Well okay then if you're sure let's try it," Naruto said as he quickly preformed the seals again, this time though he carefully lowered the tip of his giant clawed finger on top of his son's head and poured the built up chakra into him.
After several moments Boruto fell back upon his father's snout in defeat feeling nothing, "Ah dammit," he griped in disappointment, but a moment later he felt an intense heat begin to rise within him. It was happening! It was really gonna happen! "Hey dad quick put me down!" Boruto shouted with glee.
Taking the cue Naruto placed his son down on the ground just in time for Boruto's own billowing cloud of smoke to appear. Boruto felt his chakra mingling with that of his father's as his body began to expand rapidly, all the while becoming denser with new muscle in addition to height. Euphoria was beginning to overtake the boy until he was overcome by a fierce itching as golden fur began to grow across his body and a painful burning erupted at the base of his spine as nine tails of his own began to sprout. With thud after thud his nine tails grew in size and fell to the forest floor, now each akin to his father's, rivaling his own height when he tried lifting them. His lush golden fur, topped by his normal hairstyle, continually fought a losing battle to hide the young ninja's ever increasing musculature as his body began to take the form of an avid athlete, not quite as dense as his dad's but still remarkably cut. Finally, as his height continued to soar, he felt a pressure in his groin before his balls suddenly became heavier and hung lower and his penis began erecting up his six pack until it was half way up his abdominal muscles, smaller than Naruto's but Boruto felt far too good to care.
"Oh my...*huff*...Oh my God...*huff*...Dad that was incredible," Boruto beamed, standing fully to find he was now only marginally shorter than his old man while matching whisker marks began forming to join his actual whiskers, again akin to Naruto's.
"Glad you like it," Naruto said, proud of his handiwork as his tails began to sway once more. "But I guess that means it's better than "just okay," he teased observing his son's newly grown physique, a strong swimmer's build paired with a generous dick, all enveloped in an alluring gold fur, and adorned with nine fresh new flowing tails.
"Definitely," Boruto said before he, to his father's surprise, planted a deep kiss on his father's muzzle.
"Mmmph...Boruto...hold on," Naruto said, confusedly breaking the kiss, "Why are you...what does this...I mean do you really think that we should..."
"Because I want to, It means I'm horny and frankly so are you, and yes I really really want to," Boruto declared confidently, then pounced on his father, pinning the larger fox to the ground with a giant tremor and kissing him anew.
Finding this kiss harder to break Naruto began to lean back as his son ravaged his mouth and with a final gasp asked "Are you sure about this?" giving in more and more to his desires.
"Absolutely," Boruto asserted, letting his body sprawl out atop his father's, the two giants gradually becoming a tangle of limbs.
"In that case..."