A term used to describe the smooth and gentle movement between the mucosal surfaces of the two partners during intercourse.

The normal intact or restored foreskin provides non-abrasive and smooth motion of the penis in and out of itself between the mucosal surfaces of the vagina or anus, dramatically facilitating comfort and pleasure for both partners.  This minimizes friction, which adds immeasurably to the comfort and pleasure of both partners.  Without this gliding action, the corona of the circumcised penis can function as a one-way valve, making artificial lubricants necessary for comfortable intercourse. The foreskin's "gliding action" is the hallmark mechanical feature of the intact penis and a primary function.  Also referred to as the "gliding mechanism".

Image Source: www.cirp.org/pages/anat/

Image Source: www.infocirc.org