The expanding genitalia grows and splits the diaper open as the mutant pituitary gland continues its out of control process. Henry squirms in discomfort as his cock and balls mature and spread out from the destroyed diaper.
It lengthen and gains girth while hair grows around the base like a mighty mane. The testicles balloon and get hairy. Veins pop and slither around the shaft as the head and glands bulge out purple. The rush of hormones and testosterone making it excited leaking a trail on the floor as it moved further away in its growth.
It rumbles and churns as the unnatural growth continues to make it bigger and bigger. The transformation an odd feeling and experience for little Henry who didn’t understand what was happening to him. Only that it was forcing him to no longer move freely.
Soon Henry’s junk is as big as him before it settles down leaving a baby with a gigantic penis and balls. The whole process was intense and tiering for poor Henry as he drifted between awake or asleep.