The act of placing the head of ones penis inside the foreskin of another's penis.

The delicious act of two men rubbing the heads of their dicks together, with one of the men's foreskin being stretched over the head of his partner's dick. Add a little leakage (precum) from one (or both of their dicks), mutual excitement, rubbing, grinding, heavy breathing and the result is a mind-blowing orgasm for both men.

The act of placing the head of one's penis inside the foreskin of another's penis.

A homosexual act where a circumcised man inserts the head of his penis into another man's foreskin.

The process of inserting the head of a circumcised penis into the foreskin of an un-circumcised penis

As well as referring to the act of placing the head of an erect penis inside the foreskin/meatus of another erect penis, docking also denotes the act of placing an unerect or flaccid penis along the length of an exposed buttock crack. In this act (often performed in British, public, boarding schools), erections are very much frowned upon.

(verb) Docking, to dock, docked:
The act of stretching ones foreskin over the erect penis of another man.