Dylan unlocks Jeff's laptop and phone. He amuses himself for a while reading Jeff's texts. There are lots of messages with his best friend, and a lot of the recent ones are talking about the girls they think are hot. One contains a link, and Dylan clicks it. It takes him to a porn video, showing a girl getting railed in the ass. Dylan's mind is fully engaged as he watches in fascination. He's only seen a few porn videos, just briefly when his friends showed him. Most of Dylan's friends, like Dylan himself, were stuck using devices with parental controls that block porn, and Dylan doesn't have the technical expertise to get around it. Seeing someone get fucked in the ass blows his mind. It being a girl is kind of lame though. He explores the porn site, while Jeff is stuck staring at Dylan's erection.
Dylan presses it up to rest his hard cock on Jeff's face, to keep it warm. He finds a video of a young looking teen guy getting fucked. Seeing the moans of pleasure from the older man doing the fucking makes Dylan want to try it.
He sets down Jeff's phone, and grabs the laptop, resting it on Jeff's head. He doesn't want to give Jeff a body again, and besides, wouldn't a butt be kind of gross? He isn't about to lick Jeff's hole clean like Jeff did for him. Dylan wracks his brain for ideas, and the realization comes to him that Jeff's mouth doesn't necessarily need to stay a mouth, not with the power of the app.
Dylan creates a mode that will make all the changes necessary. It takes an hour to find all the right options and commands, and way more reading than Dylan would prefer. He's not sure he has it correct, but thinks, what's the worst that could happen? Dylan binds this new mode to a trigger.
Dylan puts his fingers into Jeff's ears, which triggers the transformation.
Jeff feels himself starting to change. He'd grown increasing nervous while Dylan focused on the laptop, and now, Dylan was apparently doing something to him. Dylan picks him up and sets him in front of the mirror. Jeff feels his mouth shrinking, and tongue...stretching, maybe is the right word for it. Like his tongue is rolling, but in a disturbingly unnatural way. Jeff doesn't see any changes in the mirror. When he tries to open his mouth, he finds his jaw won't open, but he can flex his tongue in a way that makes his mouth seem to squeeze together. His teeth are shrinking now to make room for his tongue to fill in the space, and his lips start to purse together, then squeeze in from the sides, shrinking and shriveling, until he finally realizes what Dylan has done to him.
Jeff's mouth is now a puckered sphincter, his mouth an anal passage. It looks awful on his face. Jeff tries to scream, but the air he pushes out comes out as a loud fart sound.
Dylan's laughter humiliates Jeff even further, and Dylan laughs harder when Jeff tries again to speak, creating another fart sound.
"This is the best idea of I've ever had!" Dylan rubs Jeff's 'lips', and Jeff feels odd sensations at the contact. His new sphincter is very sensitive. Dylan presses his finger into the middle, and Jeff discovers he can squeeze down tightly with his new 'lips', forcing Dylan to apply even more pressure. Like with a real butt, Jeff can't quite squeeze tight enough to keep Dylan's dirty finger from breaking in, and now Jeff's tongue, which has become the walls of his new anal cavity, can taste Dylan's finger from all sides.
"Woah, I can feel your taste buds rubbing against me," Dylan says. "You should feel this sometime!"
Jeff can only turn his eyes up to stare daggers at Dylan, which only seems to amuse his 12-year-old tormentor even more. Jeff resolves not to embarrass himself by trying to talk anymore. Why had Dylan done this to him?
He soon finds out, as Dylan brings Jeff's head between his legs again, a position Jeff is unfortunately very familiar with now, and the scents of boy crotch wash over him.
Dylan lines up his erection and presses himself forward. Jeff squeezes his sphincter lips together, and Dylan uses both hands to force Jeff's head onto his dick. Dylan's dick presses inside, and now Jeff can taste Dylan's dick, and his sensitive tongue feels every inch of it, even feeling the sides of the head as his tastebuds slide along it. Dylan drives in further, until Jeff's sphincter is kissing the boy's pubis, with Dylan's hairless balls pressed into his chin.
Jeff looks towards Dylan, pleading for him to back off, but Dylan rotates Jeff's head, obviously enjoying the sensations of Jeff's new hole gripping and warming his little 3.5 inch dick.
"I bet you've never got to fuck anything," Dylan says, and it sounds so much worse with Dylan's high pitched voice. "I'm going to get to today, and you'll always know I got to do it first, to you."
Dylan is true to his word, and Jeff feels Dylan pulling and pushing his head up and down the boy's cock, thrusting hard. Jeff's saliva, of which there is so much that it drools out, is working as lube.
Dylan is awash in new sensations as he forces his babysitter to ride his dick. The only thing that could come close was Jeff's blowjobs, but this feels so right to Dylan. Dylan pictures the video and decides to try something else. He pulls Jeff off his dick, and sets his head against the arm rest. Then he positions his hips above Jeff, and lines his dick up again, forcing his way into Jeff's hole. Then he rubs Jeff's hair in a circle, turning on Blow Mode, wondering what it'll do with Jeff's new hole.
Dylan starts fucking like a man, his butt cheeks squeezes as he thrusts hard into Jeff's hole, pelvis smashing into his face, and he loves the feel of his balls smacking Jeff's chin.
Jeff feels violated with each thrust, and now, thanks to Blow Mode, his new mouth caresses Dylan's cock, his tongue-coated anal passage rubbing and squeezing Dylan's cock, and squeezing extra hard when Dylan pulls out. Judging from Dylan's gasps of delight, Jeff knows it's making the kid feel amazing, making Jeff terribly jealous and embarrassed. What if Jeff's friends ever saw him like this?
Jeff feels Dylan's squirt of cum after only a minute of fucking, tasting the now familiar cum, as it spills into him, and the squeezing of Jeff's mouth guides the cum into his throat.
"Woah..." Dylan says, panting and sweating. He pats Jeff's cheek affectionately. "I'm going to do that again soon."
Dylan sets him down in front of the mirror. The hole on his face isn't gaping open, it remains tight. Jeff wonders if an adult-sized cock with stretch it out, and decides he'd rather not think about it too much. The drawings Dylan made on his face are somewhat smudged now, even the words 'Dylan's Property'. The dick drawn on his face is still recognizably a dick.
Jeff listens jealously while Dylan eats the left over pizza for lunch. It still smells delicious, and Jeff sees saliva drooling out of his sphincter, dribbling down his chin, to pool on top of the stand that still has his name on it.
What if Dylan loves this so much that he decides not to change Jeff back? Dylan might be able to do something with the Chronivac, maybe alter their parents' memories to forget Jeff exists. Then what would Jeff do? Sit under a boy's bed during the day, and be used as a sex toy every night?
With absolutely nothing to do, Jeff can only wait and let his thoughts conjure up mental images of the hell his life could become.
Dylan chills out on the couch, watching TV. He's onto Deadpool 2 now. The movie isn't as good as the feel of fucking Jeff's face. When Dylan's boner returns, he puts Jeff back against the armrest again, this time upside down. He likes the thought of his balls slapping Jeff's eyes, even though he won't be able to see his expression this time. Dylan fucks Jeff again, and it lasts an extra minute this time, Jeff's new tubular tongue making his dick feel even better. Dylan bets no one ever had a fuck this good, and he cums into Jeff's new mouth as the most incredible orgasm washes through him.