It can be difficult to picture how a foreskin is made up and where it begins and ends - even for those who own one! Painfulquestioning's original post does an excellent job in grahically displaying the action of a foreskin, but it's clear from some subsequent posters that confusion still exists regarding the inner and outer foreskin and what part they play.
I've discovered a method of simulating a penis and its foreskin which will leave you in no doubt, I hope...
You will need:
1. One of those elastic supporting bandages that athletes use after a limb injury. Some First Aid kits come with one for domestic use. If you don't have this, find an old, long, stretchy sock or stocking or pair of tights. Just be sure whatever you use is elasticised. Why? Because this will be your foreskin - and foreskins stretch.
2. An arm; preferably your own, but any arm will do! This will will be your penis - oversized, but all the better for that!
(a) If you're using stocking, tights or a long sock you should cut it open at the closed end. This will ensure that whatever you use is now tubular, like the bandage (above).
(b) Next, if necessary, cut through again to the length of your extended hand and most of your lower arm.
(c) Bare your arm and clench your fist. Your arm is the shaft of the penis and your fist, the glans (head).
(d) Take the prepared tube and pull one end over your fist until it's snugly covering your wrist, leaving the rest dangling loosly. The stretched, snug end is where the inner foreskin, the mucous membrane, is firmly attached by the frenulum to the underside of the penis. (If we weren't using your arm, I'd suggest pinning or sewing a short, tough rubber band to simulate the frenulum. But, instead, just remember it's there!)
(e) Now insert the fingers of your free hand through the loose end of the tube, and stretch it open. Fold the sleeve back over the length of your fist and carefully up your arm. The aim is to keep the changing folding point below your fist
. Obviously, if you can enlist some help, the process will much simpler.
You now have a simulated, uncircumcised penis in its flacid state. (Though it would be best if the bones in your lower arm were flacid, too!) The underside of the folded sleeve is the inner foreskin, full of all the sensory nerves; the upperside is the outer foreskin which extends along the length of the shaft to the pelvis.
But now your rigid lower arm is useful. You can mimic the effect of an erection by gripping the outer sleeve and stretching it back towards your elbow. Watch how your fist (glans) is slowly exposed, as the inner sleeve turns upside and the outer sleeve downside. If you use a silicone spray at this point on the upturned inner sleeve section, then release your grip on the outer sleeve, your 'foreskin' will slide back over the 'glans' again. This aproximates both the act of mastubation and that of sexual intercourse.
I have tried to explain every step clearly and relate them to a real penis. Because of this, it probably sounds more complicated than it really is. But do try it sometime - it works!
By the way, to the poster who queried the plural of 'penis', it's penes (last syllable neez
) or penises. Penises is commonly used.