The first thing Mike felt was the fur. It was like the beginning of an itch, but it happened all over his body. He dropped his arms immediately to pull at the neck of his tank top. Looking down, he was about to say something when his eyes flicked to his hands themselves.
"Is something wrong?" Jeff said, spotting the words forming in his dad's mouth before he instead held his hands out in front of him.
"I-- everything is changing at once--" Mike began, but developed a confused look on his face as one hand went towards his jaw. Jeff was about to say something himself when his father's face began to push forward as if to greet the incoming hand. Mike's jaw seemed to grow thicker as it did so, feeding the length as it continued push forward. The fur, as if envious of not being the most interesting thing anymore, rushed up from the tank top and quickly overtook Mike's shoulders before diverging three ways down his arms and up his neck. It was a messy gray and black tone, transitioning lighter the closer it was to the center of his abdomen.
Mike finally settled on something, putting his quickly changing hand across his still bare arm, just in time to catch the wave of fur push it away from his skin. His other hand was turned upward, letting Jeff glimps at the swelling paw pads replacing his father's palm. His fingernails were already an unmistakable set of claws common for a wolf.
"Wroa-woah..." Mike slurred as he suddenly stumbled forward. His mouth seemed to reach it's final destination as his nose, properly flattened during its journey, darkened and split, wettening into the familiar canine visage just in time to be surrounded by fur. Jeff saw a whisker or two shoot out before his father very noticeably grabbed at the crotch region of his swimming trunks. Mike almost appeared to have a confused look again, but at this point it was getting pretty hard for Jeff to comprehend his dad's facial expressions in the middle of everything shifting. Instead he craned his head to the side to see his father's legs. He was just in time to see the wave of fur rush past the bottom of the trunks and overtake Mike's knees.
Another weird noise came from his father as his knees shifted from underneath him as they began to assume a more quadrepedal stance. The balls of his barefeet rose and kept climbing until Mike's legs roughly resembled that of a dog's. Jeff assumed his father could still stand on two legs if he wanted to, however. It wouldn't be very anthropomorphic otherwise.
Mike seemed to involuntarily raise his left leg up and tap the floor a few times. What remained of his foot was swelling into a rather large canine paw. Each tap grew louder as claws even larger than the ones on his hands grew out and clacked against the floor with each step. Mike quickly repeated the pattern with his other leg. He then gave a loud huff very reminiscent of a canine, prompting his son to look forward.
Jeff was actually a little surprised as his father's head had been completely replaced at this point. His ears were flicking every other second, obviously not used to the new muscles allowing them to shift and pivot. Mike himself was looking straight forward, his mind somewhere else as his eyes took on a more speckled, yellow hue at the iris.
A deep shudder moved through the Mike's very wolfish form, starting at his head and working its way down. His eyes suddenly went wide as his ass seemed to pitch up by itself, causing both father and son to turn their heads toward it. Bent just so, the spot between Mike's swimming trunks and wife beater grew a small lump that seemed to elongate slowly, until more fur overtook it and it quickly flourished into a bushy wolf's tail. It was just as gray and black as the rest of him at this point.
"Is…that it?" Jeff said after a moment of nothing else happening. As far as he could tell, the growing of tail completed the visage of a 'wolf-man'. Anything more would probably make his father look perhaps too feral. Mike didn't immediately reply, instead leaning back until he was on his knees. He looked back at his feet-- or rather paws, which neatly folded underneath him as to not get in his way, and simply pushed himself up back into a stand.
"Ah..." Mike started, but stopped once again. He moved his his lips and jaw around, testing the functionality of his new face muscles. After a moment, he seemed to be satisfied and talked very deliberately, "Everything feels really…different."
"You still sound exactly like yourself." Jeff noted, "if you don't like it we can change you back now."
"No," Mike said quickly in a still deliberate tone, "let me-- let me just get used to my new self."
Jeff stayed silent as his father clenched and unclenched his claws a few times, and continued as he reached behind him and squeezed the base of his tail. Mike's eyebrows raised and his hand moved toward the front of his trunks before he stopped himself. Mike, suddenly very aware of his son, looked straight at him.
Jeff simply stared into his father's very brilliant eyes, seeming to have a glow behind them as the light of the room were easily caught by them.
The two stared in silence for a brief moment before someone spoke up.