Your parents were about 50 and their ages were starting to catch up with them. A few wrinkles, being a bit less active, and more and more grey hairs. So you figured you'd go ahead and mess with the age function a little and figured you'd halve your father's age to 25. His hair darkened, muscles strengthened, and he generally got a pretty good infusion of youthful vigor. You then pressed the button again as the matured stud was about start trying to get his much older partner to maybe go have sex and regress to about 12 and a half where his pecker started to work. Despite married the now more youthful boy was blushing as he tried to reach for his wife's hand as his adult clothes shrank into just some shorts and a shirt. A third halving and the shy boy became a more confident kid of 6 years old who just went to sit in his wife's lap, and then he became three years old and then 1 years old that was closer to 2... press press press and at some point halving months into weeks into days, into hours, into minutes, into seconds left very little for a newborn to regress into. You began wondering if you could push him any younger as you pressed the regression button, and then the little baby being coddled by his wife regressed into his wife's belly.
"Woah..." you whispered as your hand pressed the button again accidentally as your mom's belly shrank back to normal... "umm..." you wondered as suddenly you felt a pressure in your balls. "Crap... Did I just unconceive dad?"