in-and-out movement; pistoning
Slang term for the thrusting motion during sexual intercourse. Used in explicit contexts.
He quickened the rhythm of his thrusting.
Alternate kanji spelling; less common than 抽送.
Compound of 抽 (extract, pull out) and 送 (send, move forward), describing the back-and-forth motion. The exact origin as a slang term is uncertain.