Ben started to cautiously work his way into a crouched position, shuddering suddenly and letting out a soft grunt as he relaxed his new arms and they brushed against his hips. As he reached his new, full height, thankful for the lofted ceiling of his top-floor apartment, he slowly began working each of his new appendages. First flexing his hands into fists, moving each finger, then moving onto his biceps, triceps, and eventually his new pectoral muscles. He began pondering what he could do with an extra set of helping hands when something caught his attention.
"...100%. Transformation commencing."
The display on his laptop was unchanged from before the change began. Ben bent over the screen and worked the touch pad to make sure it hadn't locked up. Relieved that it was still functional, he was still concerned that there were no options or status displays as followed his previous change. He stood back up, perplexed, just as the pain began again.
This time the stabbing originated from his groin, not from his greatly enlarged, two-foot bull member, but adjacent to it. Once again Ben was unsure of what was coming, especially if the problem was a threat to his bull-hood, and as such could once again do little to help it along. The pain, however, threatened to throw Ben to the floor. He stumbled to the side, managing to catch the door frame to the kitchen. He gripped it tightly with all four of his leathery arms, ducking his 8'5" stature down below the top of the frame. He reared back, using his horns to brace his head against the frame as he strained to look down at what was now happening.
The pain quickly spread from not just the front of his pelvis to the testicles themselves. Just barely able to see what was happening, Ben realized that his scrotum, already resting against his legs and extending most of the way down his thighs, was growing. Pain ripped through the sac, causing Ben to grip the door more tightly, as the scrotum began to distort slightly. The growth wasn't occurring vertically, which would have left them resting below his knees, but horizontally. Straining his neck, horns digging painfully in to the door frame, Ben realized that what had previously been two huge testicles was now four equally large orbs. His normal dual sac having grown to accommodate the quadruple chambers necessary to house his munitions factories.
Yet the overall pain Ben was experiencing had not yet subsided, despite having left his sac. It was now focused on a single point on his pelvis, just to the left of his cock. Being unable to strain his neck any further, Ben turned his head back towards the ceiling letting out of a painful grunt. Despite not being able to see his groin from that angle, he was acutely aware of what was happening. Slowly a second member forced its way forward through next to Ben's present cock, brushing against his former member and ball sac. The pain relinquished as soon as it had begun emerging, and he could feel both members standing at attention, veins pulsating with every powerful heartbeat.
Ben slowly twisted his neck, moving his head and horns carefully through the door frame. He dug each of his four hands out of the indentations he had carved, splinters of paint falling from under his thick, black nails. He cautiously took a several steps backward, testing his weight with each movement of his hooves. Once he was securely back in the living room he glanced at the laptop.
"Transformation Complete. Sample recorded to database for future examination."
The message was accompanied by a host of options, all of which Ben didn't have time for at the moment.
He turned back from the laptop and looked down at what had become of himself. As expected, he was now sporting two giant penises. His original on the right had remained unchanged during the last few minutes, while the new one on his left was several inches longer, perhaps 2'3", and had slightly more girth. He gripped each one with his new lower arms, starting at the head and slowly working way down the shaft. As he reached the base, he moved slowly to his testicles, working two in each hand. The leather of the sac and each hand's three digits bolstering his strength.
Still working his balls in his lower hands, he firmly gripped each shaft with his upper arms, deciding what to do next.