Ass Growth

Stories in which the growth of someone’s ass (or arse) is significant.

Related: Belly Growth; Breast Expansion; Detachable; Foot Growth; Getting Handsomer; Gradual Change; Increased Libido; Male Pregnancy; Transformation; Voice Deepening.

Child of: Other Physical Changes.

Top Stories: “Above average”; “Bulking”; “Reality Pack”; “Mysterious kidnapping”; “Under control”; “OmniGro”; “Spice up your life”.

Recently Updated: “Spice up your life”.

14 stories found. Total word count: 373,369.

• Above average by Ziel  CockUp Cock HyCock HyCum HyMusc MuscUp Musc AssUp Retcon  Alan starts out as just your average college boy. Then a strange, magical artifact comes into his life, and he starts becoming bigger… almost remembering the ways things were, when his muscles and cock weren’t, with each orgasm, more and more above average. As the effects spread, Alan knows he must understand what’s happing to him and his friends—and also that he must be the biggest, most muscular, most hypercocked stud of all. Added Apr 2013 Updated Dec 2018 28 parts 130,435 words 218,868 views 4.5 stars (88 votes)

• Beefcake by Zero  CockUp Cock MuscUp Musc AssUp Handsomer Taller SizeUp  They say you are what you eat—especially true for magical foodstuffs with growth-inducing powers—and wimpy freshman Bradley is about to take a bite. Added Feb 2021 1,591 words 6,856 views 4.6 stars (7 votes)
• Bulking by Proteus  MuscUp Gut Musc AssUp Grad Hairier  Sometimes, when people have a crush on their hunky roommate, they act on it by secretly trying to make the guy progressively hotter. Added Mar 2013 6 parts 7,143 words 39,400 views 4.8 stars (13 votes)

• Himbo pussy serum by BaraBootyEater  CockUp Balls Cock MuscUp AssUp HairDecr  Josh and Jason are a pair of horny bio-engineering students who’ve created a serum that can cause some muscly changes to those they give it to. Added May 2021 1,126 words 5,840 views 3.3 stars (9 votes)

• MissinGRO by Ziel  Cock XBalls XCock XArms XLimb AssUp PSD SizeUp  Javier discovers to his delight that encountering the infamous Pokémon glitch Missingno can have unanticipated real-world effects. Added Mar 2017 5,534 words 9,056 views 5.0 stars (8 votes)
• My new favorite app, Cockr by Clearlyhere  CockDn NoCock Cock Musc AssUp Det App Dom Swap Series  John is out of money and finds out about new app where his huge endowment could make him some serious cash. Added Jun 2017 Updated Sep 2017 5 parts 13,713 words 29,054 views 4.7 stars (28 votes)
• Mysterious kidnapping by Joven  CockUp Balls Cock MuscUp Musc AssUp  Jared and Derek are traveling abroad when they’re suddenly kidnapped and secreted away in an isolated room… naked. They naturally become aware of each other’s junk, though Derek isn’t too pleased by Jared’s attention. But the situation with their equipment only gets more intense… Added Feb 2018 Updated Apr 2018 13 parts 22,924 words 22,893 views 4.9 stars (15 votes)

• OmniGro by Whatinsomnia  CockUp Cock HyCock NipCum MuscUp Musc AssUp SizeUp  Dissatisfied with the speed at which the current OTC dick growing serum works, Eli, a brilliant scientist in his own right, sets out to make his own super-powered serum. Eli wastes no time in breaking in the new concoction on himself and his boyfriend. The results speak for themselves and their new product revolutionizes the world as they know it. Added Mar 2016 3 parts 45,143 words 20,076 views 4.7 stars (7 votes)

• Reality Pack by Thorn  CockUp Cock MusBr MuscUp Musc AssUp BellyUp Grad Taller PSD Hairier App AgeDiff Virgin Inc Bro Dad  What happens when the program you’re working on for school has a downloadable mod? You investigate it of course! Added Nov 2020 Updated Feb 2021 15 parts 79,094 words 23,623 views 5.0 stars (24 votes)

• Spice up your life by Musclesaber  CockUp Cock MuscUp AssUp BellyUp Taller 4th of Jul Pandem  Roommates Sam and Collin try to return to a life of normalcy after the pandemic. Trying to have a get together with friends, Sam buys a new spice pack at the store that has some surprises in store for the pair. Added Feb 2021 Updated Jun 2021 7 parts 20,934 words 15,143 views 4.9 stars (19 votes)
• Stories to tell in the dark by Thorn  CockUp Balls Cock MuscUp Gut AssUp BellyUp DeeperVoice Taller SizeUp Fatter Infl  Sean discovers a book that is filled with some surprising stories. Added Apr 2021 2 parts 9,685 words 7,055 views 4.8 stars (25 votes)

• Under control by Alakazam1988  CockUp Balls Cock MuscUp Musc AssUp Grad Taller SizeUp  Rylan is enthralled as his roommate, Peter, seems to be growing all over—though Peter denies anything is happening, and no one else seems to notice either. Added Apr 2020 Updated Aug 2020 5 parts 22,139 words 21,931 views 4.9 stars (25 votes)

• What a dear deer boy by Thatbadwriter  CockUp Cock HyCock MuscUp AssUp Giant PSD SizeUp 2Animal Hairier Fur  Eric’s undersized brother Jayden finally hits his growth spurt—then keeps hitting it. Added Feb 2021 Updated Mar 2021 5 parts 12,430 words 11,484 views 5.0 stars (10 votes)
• WYRD: What You Really Desire by RDR  NipCum MusBr MuscUp Volup AssUp  Marco is sick of being a small guy, doing what he can to fix the issue. When hope seems lost, a pop up appears on his computer asking what he really wants as if it were going to give it to him. But what does Marco really want? Added Apr 2021 1,478 words 3,359 views 4.6 stars (5 votes)