You saw that your watch was set to 7:00 for some reason. You turn the watch's hand back an hour and then heard your sister Jamie shriek. You quickly look to her and saw that her growth spurt had reverted. Her clothes were baggy and her bra cups were trying to carry some pointy nipples. Now instead of being the tallest girl in her grade she probably was one of the smallest.
you quickly asked "what happened?"
she glared at you and shouted "I Just Shrank! Look at me... i'm like a year younger."
You wondered something and turned the watch all the way back to 12:00 or basically noon with the arrow pointed at your sister and with each crank you saw her shrink farther and farther into a six year old drowning in her 12 year old clothes. The only reason Jamie didn't notice what you were doing was because she was scared half to death by her swift regression.
you apologize and say "I think I get why you had just been shrinking... I think this watch can age and regress people... probably about a year an hour... or about... a little more than 6 days a minute... 365 days a year."
Jamie calming down said "fine... I get that what you've done so far was either accidental or experimental... Just please turn me back now..."
you nodded and spun the knob forward allowing Jamie to grow older and older with each revolution. If didn't realize how loose the actual knob was considering the thing had spun like a wheel. You assumed that it had some good friction to it and jamie would grow in small bursts, but you quickly realized that at the rate the watch was going she was going to be a granny. You immediately halt the watch and saw a girl who was nearly a woman with tattered clothing around her. She was also panting while cupping her now E-cup breasts.
you apologize quickly and then turn away and elaborated "I didn't expect the knob to move that quickly." You look to the watches knob expecting the thing to be moving like crazy but interestingly enough it wasn't budging an inch. You wondered and knelt to the rug and rolled the knob on the ground and found that it didn't even move like a normal watch might.
Jamie layed over you with her much more mature body and you felt her naked breasts rest on the back of your head and asked "The heck are you even doing with that watch now?"
You said "It only seems to move when I change the time... not when it comes in contact with some random object though. So while it may spin crazy if I flick it it wont do anything If you put it against a sand belt... probably."
Jamie asked in a slightly softer tone "So are you going to do something about this body?" She puts her hand on your crotch and you turn backwards to see what she's doing, and you see lust in her eyes. You suppose that should be somewhat expected, her body just matured extremely quickly with no sexual stimulation... of course she'd probably feel a little horny. You decide to act quickly and...