Typical uncircumcised male masturbation technique. Uncut males typically masturbate by concentrating their massage on the penis’ shaft. They don’t need to caress directly their cock-head, as the foreskin movement resulting from the shaft massage takes care of the cock-head for them. Indeed, the frenar bands (the elastic ring at the tip of the foreskin) gently stroke the glans both on their way down and their way up, ensuring the glans’ simultaneous stimulation as the uncircumcised men knead their shaft. Cut men, on the other hand (!), need to knead their cock-head directly to achieve the same result, causing lube to become an almost essential rig for circumcised males.
The only moment the foreskin would be a nuisance is during ejaculation. During this event, sperm needs to be propelled forcefully in order to maximize the likelihood of impregnation, and the presence of the foreskin in front of the meatus (opening of the urethra) would obviously counterpoise this intent. To avoid this, the ejaculation sequence includes two safeguards. First, a forward thrust (simultaneous contraction of the abdominal and hindquarters muscles), which has the benefits of both pushing the foreskin to the back of the glans and bringing the cock-head nearer to its goal. Second, a transient hypersensitization of the cock-head that fosters a momentary suspension of the male’s thrusting move (preventing the foreskin from sliding back too quickly) as the first 3 or 4 squirts are ejected. In this video, we see the later occurring : as the ejaculation occurs, the male’s massage rapidly diminishes in amplitude to avoid stimulation of his sensitive cock-head, but the longitudinal displacement of his hand resumes when the bulk of his semen has been expelled.