AN: Given the speed of the time travel things are moving too fast for any sort interaction to occur so I wrote Mike always standing in front of the mirror for the remainder.
An entranced Mike watched as he continued to go backward in time. Even though he had regressed into a young man in the prime of his life and erased his family, he still wasn't close to becoming the target age he picked out when he programmed the Chronoivac. And given the set speed of the time rewinding where a second equaled a day at that rate it would still take more than a hour for him to reach it. Mike grinned at the number he picked for his final age, imagining just how surprised others would be if they knew just how young he planned on becoming.
Despite his excitement Mike remained patient as he looked in the mirror as his body returned to adolescence. His body grew somewhat lanky and skinny. As for his clothes they morphed into a pair of jeans and a t shirt depicting the logo of a rock band he was way into back in the day. Becoming a teenager again was a strange experience as he was thrust into the throes of puberty and the deep end of hormonal activity. This surge caused his youthened dick to instantly become erect and hard, the organ tenting the crotch of his pants. Overcame with horniness Mike stuck his hand down the front and grabbed hold of his big guy. Pumping his cock Mike began to masturbate while thinking of hot girls, both from the future he was leaving and the past that was currently his present. It didn't take long for him to cum leaving a sticky white splotch on the inside of his briefs. High from the orgasm he pleasured himself two more times, during which he lost track of time as he enjoyed his sexual vigor. The lustful haze lifted when he eventually grew younger than 13 and left puberty behind.
Returning his full attention to the mirror Mike saw his body was making the transition back to childhood. Sparing a moment to check his shaft and balls (which had become flaccid) he noted a slight decrease to their size and shape. Seeing the proof that the time travel regression was starting to effect the development of his manhood got Mike excited as he started thinking about their future fate. Focusing on his reflection he observed the changes, only becoming really interested when passed the 10 year mark and began slowly dwindling through the single digit ages. His body continued to shrink in height and lose all signs of maturity, becoming less defined in the process. By this point his clothes consisted of t shirts, pants and shorts; all sporting a childish design appropriate for his then current age. But the best part of this section of his regression was that his adult teeth were replaced one by one with baby teeth. The sensation of the teeth sinking back into his gums to be replaced by a smaller version left a weird funny feeling in his mouth, though he never the less enjoyed it.
At around age 7 Mike began to think about what made him choose the time travel option instead of making it so his return to the past was instantaneous rather than slow. The answer was that late one night when he was surfing the channels he happened upon a movie called Wishmaster 2 about an evil genie who grants a person's wishes in the worst possible way. It was just starting and the scene he saw was a burglar making a wish that he was never born. The djinn granted the wish by slowly regressing the man, first into a young man then a teenager followed by a child than a toddler to finally a baby that just disappeared. While the concept of being made so young you cease to exist was supposed to be horrifying, Mike found himself aroused by the sight of seeing an adult go backward through all those developmental stages in reverse. It was an experience he wished he could experience for himself, minus the whole being unborn part. So when he read the description of the Chronivac's time travel option he saw his chance and seized it. And thus far it was everything he hoped it would be and more.
Mike smiled widely as his youthful transformation was approaching the final and most exciting stage. As he passed 6 years old he felt a few of his recently acquired baby teeth fall out and vanish. Mike then kept his mouth open so he could keep track of how many he had left, hoping he wouldn't lose them all by the end of time traveling journey. Nervously hopping in place he counted down as the minutes agonizingly took forever to pass by. "5...4...3" he breathed aloud as his body became littler and chubby with regained baby fat. Almost half his teeth were gone, his hair short and wispy and his face becoming more cherub like. It was a face Mike had only seen in the earliest volumes of the family photo album. About a minute before he reached 3 his underwear changed becoming a pair of pull-ups. The change from fabric to crinkly plastic padding was welcome but still not what he ultimately wanted.
"Come on, almost there...just a little more" Mike whispered, hardly paying attention to his new high pitched voice as he was too focused on his training pants.
Squirming in place and shifting from foot to foot he went back to counting the minutes. At 2 and a 1/2 it finally happened, the clothing shift he had been waiting for. His breathing quickened as he felt the pull-ups thicken and puff up, spreading his legs apart as muffled crinkling could be heard beneath his pants. All this pointed to the fact that he was now wearing a diaper. Reaching down to feel the front of his crotch Mike could feel the hidden padded bulk as a dreamy smile crossed his face.
"I can't believe I'm really back in diapers."
At that moment Mike really thought about his situation. A few hours ago he was a 50 year old adult with a job and family and now he was a 2 year old baby with none of that. He now had the freedom to do whatever he wanted, with certain limitations. And thanks to his new absorbent padding he could now go to the bathroom whenever he wanted too. Mike's inner contemplation lasted long enough for the regression to come to an end with time beginning to move forward again at the natural rate. But what really broke he out of his thoughts was the disappearance of his shirt and pants leaving him in just his diaper. This wasn't surprising as he his parent let him run around the house in just that when he was a baby, to make changes easier and to let him have fun. Looking in the mirror Mike saw he reached the age as he saw a 1 year old baby boy staring back at him. The adorable tyke who was just old enough to be considered a toddler was clad in nothing but a vintage Pampers with cute teddy bear and number designs. Transfixed he reached out a hand as his reflection copied him, proof that he was indeed looking at the new him. Grinning at his infantile appearance Mike noticed that his mouth was mostly gums save for four baby teeth, two on top and two on the bottom, the sight making him grin all the wider.
Checking his room he saw it had settled, becoming his old nursery which he recognized from old photos, complete with crib, changing table, dresser and toy box. Downstairs he could hear his dad watching TV and the faint sounds of his mom washing dishes in the kitchen. Satisfied that his parents were busy Mike went back to checking out his baby self. His body was completely smooth and slightly chubby with baby fat, particularly around his short arms and legs and his belly which spilled over the waistband of his padding a bit. Speaking of his diaper Mike noticed just how old the Pampers disposable was, having none of the advancements of the ones from 2022. Still it was soft and comfortable and would serve the purpose of doing his business in when the time came.
As Mike inspected his garment he realised he had neglected to check on his boys since he was a teenager. Grinning in anticipation he pulled back the front of his diaper to peek inside. The sight that greeted him took the toddler's breath away. His penis was a shadow of its former self, now just a tiny nub resting on two marble sized prepubescent balls surrounded by a hairless field of skin. Seeing he now had a baby dick didn't demoralize him as he knew the kind of monster that awaited him when he grew up. Until then he would make do with playing with his new shrunken privates when his parents weren't around. Letting the waistband snap back into place he faced the mirror once again. Deciding to have a bit of fun Mike embraced his new age by doing a goofy little dance to show off his Pampers. It was difficult because he was still learning to walk but with determination he managed to shake his padded groove thing in celebration.
"'Imma in diapas...Imma in diapas...Imma in diapas" Mike happily sang while struggling to control his newly developed lisp. Each and every move was copied by his reflection, even the big finish where he turned around and stuck out his diapered behind while stomping his feet.
Despite all the dancing he just did he still felt full of energy, energy he just had to release or else he'd go crazy.
So excited was Mike that he ended up...