Manual sexual activity in which the female partner uses her hand or hands to masturbate her male partner to orgasm. This method of relief is often used to avoid or delay sexual intercourse, either to preserve virginity or for other reasons - e.g. environment, the need for haste, menstruation, or as an occasional alternative to other sexual activities. Lubrication is essential for mutual comfort; the most commonly used substance is saliva.

The term derives from the actions of an enthusiastic barman in a cocktail bar, shaking the cocktail mixer vigorously up and down to combine the spirits and mixers and to partially crush the ice.