Amyl nitrate and related volatile solvents, usually supplied in a small brown glass bottle. Name derives from the fact that the liquid used to come in glass ampoules for medicinal use as a cyanide antidote that 'popped' when broken open. Nowadays often supplied as 'room odorisers' or 'aromas' in order to get around medicines legislation, and used almost exclusively as a recreational drug and sex aid by gay men. Not actually illegal to possess in most countries. Works by relaxing smooth muscle thereby dilating blood vessels, causing a rush of blood to the head and drop in blood pressure, resulting in an intense but short-lived high. Also relaxes the muscle of the anal sphincter, thus facilitating the entry of foreign objects, especially large penises.
Russell took a deep inhalation of poppers just before Mark shoved his 10-inch cock into his arsehole, in order to ready it for the pounding it was about to receive.