A few weeks after the park incident, you were lying in Noah's bed, trying to ignore the fairly sizable bulge in your pajamas. You were settling in fairly okay after the doctor had determined amnesia and were starting to learn of ways to hide your sizable endowment.
As you lie on the bed, the kid in your old body suddenly appears in your bedroom, holding the stone. Before you can move, you can't - and you realize he has wished that you cannot. Trapped on your bed, you feel fear start to come on.
"Remember when I said I would make you even bigger than me?" the kid smiled wide. You suddenly feel that you can move your head and face, but cannot speak. Silently you plead with your eyes that you're already big enough. The kid shakes his head, "you wanted to know, so now you get to".
As he finishes, you feel a light pressure sensation in your penis. Moving your head to look down, your eyes open wide as you watch your already-noticeable bulge begins to swell larger, your penis starting to outgrow your custom underwear. After a few moments, the growth stops, but you are definitely bigger than before.
The kid smiles, "you know, for all of this I'll at least give you something positive". Once again you feel a light pressure, but this time in your balls. You can only assume they are also growing, and although not as dramatic, you can see your bulge swelling just a little more. Again after a few moments, the pressure abates.
"That's enough growth for now... but be warned, I can visit again at any time." the kid waves and disappears. Just like that, you can move again. Immediately you jump up and run over to the mirror, and you can already feel that your underwear, fitting perfectly before, was now too tight.
Looking in the mirror, you are dismayed to see that the bulge looks absolutely unreal on a teenager your age. Putting the ruler next to your cock, you find that it has grown to 9.6 inches soft, a full 3 inches longer than it used to be soft. Most changed are your balls. Previously they were a little on the small side for a cock of your size, probably about the size of golf balls. They were now tennis ball sized, almost ranging on too large territory. Sitting on the edge of the bed in shock, you manage to pull your underwear back over your massive endowment. It stretches, barely managing to cover all of your genitals.