Bucking Broncos
He felt his balls inflate, the skin becoming tough and leathery. his skin pigment turned black, spreading up his erect cock. as it moved up his shaft began to grow. his glans flattened into his new flared head, medial ring bulging out.
Blubbery Muffins
Not to be outdone, his furry sac began to flesh out as well; his grape-sized testicles inflated, first to the size of lemons, then to the circumference of ripe grapefruits.
Breed of the Week
Kay's belly swelled steadily like a beach ball inflating with air, and just as large...if not larger. he could feel the tussles and squirms of the strong, heavy wolf pups all kicking inside him, hitting all his sensitive spots.
Curiosity filled the cat
Max slowly opened his eyes, lazily blinking as he tried to clear the sleep from them. Unconsciously realizing he needed to clear his vision, he tried to use his hand to wipe it away, only to find that he couldn't move either of them. Blinking several...
An Unexpected Third
A rush of hot cum was being pumped into his gulping dick and the only place it could go was into his balls, inflating like balloons and becoming hot with not only his load but his best friend's. they were sloshing around inside, mixing and becoming on.
The Sands of Pleasure: Familiar Bearing
It had grown at least 3 inches thick now, and his balls inflated to stay in scale. roniv murred as she watched the development, eager to see if she could take such a cock. "oh please, master! would you please fuck me with that big, thick monster?!"
Tales of the Sewer and Beyond
He grunts loudly, his cock extending 2 more inches and his balls inflating slightly.
Xochipilli Ch. 2
Jake's balls inflated at the snake's command, and his climax began pumping literal quarts of his seed through however many feet of his dick.
Houndoom TF
Maybe it was due in part to how sensitive his body was thanks to having his member being packaged away all the time instead of flopping out as it once did, or perhaps it was due to all of the hormones which flooded throughout his body following his balls inflating
Annalee and the Wrestler
Shi spread hir legs and straightened, looking in a full-length mirror set against the wall to watch as hir massive balls inflated, stretching around the male's head and upper body.
Chapter 1: The Spell
His balls inflated, and the extra weight they gained felt marvelous. he was beginning to feel quite pent up, his balls tight with the need to release. "i've finally got the endowments i deserve. congratulations, thunderlane. your prince is pleased."
Just a little release (Applesandwich commission)
While shoulders and biceps bunched up and got pushed aside by accessory muscles that suddenly had enough bulk to outclass other men's torsos, testicles inflated and churned to produce more and more seed.