By now, Jake's two-incher had grown to it's full length and was throbbing fit to burst. Jake could not wait any longer, and neither could Finn. Jake penetrated Finn's virgin bootyhole with gusto, and began pumping.
"Oh my gosh, Jake!" moaned Finn, "That feels so Algebraic!" Jake said nothing, and continued pounding. Being 13 years old Finn did not have much of a wiener to speak of. Nonetheless he began massaging the spot where a penis should be, crying out in pain and pure ecstasy while he did so. They did this for about 26 minutes, before Jake suddenly stopped. "What's the matter, buddy?" Finn questioned, "You run out of juice so soon?" "Naw, man. I just had a great idea! You remember my stretchy powers? The ones that make me grow huge?" Yeah?" Finn answered cautiously.
Suddenly, Jake's two-inch-long cock expanded in Finn's ass. It grew and it grew and it grew. Finn began screaming, but not because he was in pain, but because his body was now being filled with Jake's beautiful genitalia. Jake continued to grow until his doggy lipstick was 300 feet long as wide as a city block.
"Jake... You really are a true bro." Finn squeaked out, barely able to speak.
"Thanks, dude." Jake said, and smiled. He knew that now, Finn and himself were inseparable friends. Nothing could ever come between them. And with that heartwarming moment, Jake continued. Jake kept pumping and grunting, back and forth, in and out of Finn's backside, his doggy balls slapping on what was left of Finn's body.