Curious to see the device truly tested to its limits, you decide that leaving your Dad--now your kid brother, your rearranging memories are telling you--an adolescent wasn't enough of a change. Deciding to see how far back he could go, you announce that it's time to clean up the tools. Diligently, your former father, now kid brother, begins collecting the various tools and placing them back into the toolbox. As he does so, you take advantage of his back being turned to hit him with another dose of the device.
Your former Dad goes through puberty again as his height shrinks, all body hair retreating into barely visible peach fuzz--if that, and his oversized hands and feet becoming more appropriately sized for a little boy rather than a gawky adolescent. When the dose was finished, your former father had gone from 14 to age 9, according to the device.
"Good job, kiddo. Now let's wash up and get ready for dinner," you suggest rather paternally, and your former father's obedient head bob strikes you as odd until memories of him being your son pop into your 28 year old mind. As he scurries away towards the bathroom, you aim another dose of the device at him before he's completely out of sight.
You then take your time getting up yourself as you collect the wood piles and screws together for your remodeling project. It isn't until you hear a crash coming from the bathroom that you stop what you're doing and immediately strike out for the bathroom, where you come across your 3 year old son on the floor trying desperately to pick up a slippery block of soap that was just a bit too big for his small pudgy hands, the bathroom sink running furiously, and the clay soap dish you remember making in third grade for your mother on the tile floor, broken and in pieces, sharp pieces that your son was very dangerously close to scratching himself up on if he wasn't careful. Feeling an immediate rush of adrenaline, you swoop in and scoop up your small and pudgy son just before he can brush against the broken bits of enameled clay.
"Run into a bit of trouble, buddy?" you ask, in a good-natured way, trying to diffuse the situation, and your desire to snap at him, knowing that that wouldn't do anything to fix the situation.
"I was washing up like you told me, Daddy, and then the soap fell and I couldn't pick it up," babbled your son as you settled down onto your knees and put him down on the ground so as to keep from holding the squirming toddler for too long.
"Seems like you still need a bit of help there... as you're even dirtier than before," you say, turning him around to face you so you can get a good look at him. Not only was he covered in dirt from his misadventure in the living room, but his little wet adventure and fumbling around on the ground and brought another layer of grime into the mix.
"You know, let's have bath time before dinner tonight," you say, making the decision now.
"No bath," says your son immediately. He was going through a phase where he liked to say no to things--whether he actually wanted to or not.
"Then no dinner either. No bath then no dinner," you state very clearly so your son fully understands the consequences of his choice. He frowns, rather cutely.
Just then you hear the back door open and close, and your son's face immediately lights up as he squeals, "Mommy!" before shooting past you. Memories of your girlfriend from your original life where your son is your father, now have her as your wife and the mother to your son. Deciding to take advantage of his back being turned once again, you pull out the device and aim a small dose at your toddling son, who begins to have trouble walking as he continues down the hallway to where Mommy was taking off her coat and preparing to scoop up her baby boy, who was increasingly becoming more and more of a baby as he toddled, then stopped and fell to his hands and knees and crawled his way to her, his squeals becoming more and more incoherent as he forgot how to speak. He was soon in his Mommy's loving arms and shrank even within them until according to the device, he went from a year and three months old to being only three months old. The change effected more than your son, as your wife seemed changed--her breasts swollen with breast milk, and some added baby weight now rounded her out a bit. Amazed that the device had switched from displaying years to months as well--though the option to regress only by years seemed to be in place.
"Did Mommy's little man miss her?" cooed your wife to the babbling baby in her arms.
Curiously the - button was still lit, indicating that the potential to get younger was still possible. Not liable to quit now, you give the button one more press, just to see what it would do, and suddenly the age jumps from 3 months old to Conception. Just before the emitter engages however, a text box appears on the screen asking: Would you like to save original DNA?
Deciding that saving would be the best option--he didn't want to destroy his dad, just test the limits of how far this device would go--he selected the "yes" option and hit enter. Immediately a beam came out from the device hitting both your son and your wife simultaneously.
The tiny infant in her hands shrank further, as development undid itself rapidly until your son was nothing but a newborn and then pop he disappeared and your wife's belly grew to nine months pregnant, almost causing her to lose her balance until you step forward to help her.
"Honey, help me to bed, will you?" she asks as she places her hand on her eight month belly.
Nodding, you assist her to the bedroom, watching in awe as her belly which had grown so quickly now seemed to melt almost as quickly. By the time they had reached the bedroom, there was no sign of your wife being pregnant at all, in fact she stopped in the doorway and shuddered, before opening her eyes and locking them with you and saying, "Forget the food, I wanna eat you for dinner."
Feeling suddenly rather horny yourself, you both tear off each other's clothes and hop into bed. At first she's insistent on being on top, and as your wife rides you, you feel a strange tingling sensation in your groin. Rather than feeling like something was coming out, it felt like something was being sucked back into your penis, it isn't until the tingling sensation is finished and your wife resting her head on top of your chest that you think to look at the device, which was on the night stand. Tilting it with your hand, you see that the age bracket has now separated into that of sperm and egg, counting down the minutes of age of each. With a sudden realization, you figure out that you had just unconceived your former father. You at once feel shocked at how far the device could go and yet simultaneously horny. Where before part of you'd once been a sperm in his balls, now the tables had truly been overturned, and he was a little wriggler in yours. How closer could a father and son truly get?
"Ready for another round?" asks your wife, and deciding to leave the philosophical musings until after your son had been reconceived, you smile and help your wife back up and begin to roll your hips in rhythm with her until the familiar feeling of ejaculation occurred, and you felt your load blast into your wife's waiting and guaranteed fertile womb.
After this round, you both are well and truly spent. Your wife then begins to caress you as she lays back and raises her legs a tad--to increase the chance of conception you know innately, suddenly knowing that without having to be told. After a few minutes of this, she then tires of that and gets up off the bed and hurries herself into the bathroom to clean up. Taking the opportunity, you look at the device on the nightstand to see that your son had indeed been reconceived.
"That was a fun experiment," you muse, before resolving that it was time to make him older, at least a little bit for now. It might be fun to be father to your father for a few days, and now that you'd actually experienced conceiving him... it was starting to feel extremely natural to think of him more as your son and less as your former father.