The expulsion of air from a rectum after anal sex.
An assqueef occurs when an object, usually a penis, creates a vacuum of air inside the rectum, and continues building up pressure, until audible release is inevitable. Note that an assqueef is not a fart.

Intelligence agency term for "psychological operation". A government or corporate-sponsored operation, usually taking the form of a "terrorist attack" or "crazed gunman on a spree", with the intent of panicking the public into demanding more police and laws inhibiting freedom. Psyops are usually carried out by drugging a civilian or group of civilians with aggression-promoting drugs, psyching them up, arming them, and sending them out to commit mayhem. Government-sponsored terrorism. See also blackshirts, conspiracy

release of air during anal sex

when a girl tries to blame a fart during sex as a queef usually to no avail because of the smell

Pretty much, just another word for a fart. If you want to be more immature about it, just use the word Ass queef.

Typically, when a person has flatulence they would call it a “fart”. Here, in Atown (aka Anacortes, aka fagtown) we call these ass queefs.

when after gay anal, and your ass has air trapped in it and you decompress, you let out a queef like fart.