A foreskin protects the glans from possible damage. The foreskin survives well using a delicate balance of body secretions to keep it well lubricated. The lubrication is increased with sexual activity. A penis/ foreskin that is not washed enough can cause problems and can build up a whitish substance with a rather unpleasant odor referred by many as "cheese". A candid remark by a mate about this odor or fact that it is "cheesy" looking, may drive a guy to give it better care. However, an obsession with cleaning, especially with strong deodorant soap, can remove too much of the natural lubricant creating a dry, tight foreskin. Guys should remember to rinse it well after washing with mild soap, however ANY soap residue allowed to remain will dry and is bound to crack the foreskin, make it guitar string tight and uncomfortable. For those having problems with tightness, sometimes a very mild lubricant like baby oil or your choice of lubricant can keep it soft and pliable, and working the way it should. For those, all sexual activity should be with lube.