So you're a grower not a show'er too. Like me. I used to think being a "grower" was a curse; like when a woman might try to grab your crotch and not get a handful of cock. But now if that situation comes up I just tell her I know magic. Just watch me and seerl how much it grows.
I would slip a middle finger deeply into your asshole to stimulate your anus and prostate while you jerk off until you cum. It'll make your curled toes curl even more with pleasure. Woof !