An Eastern European sexual practice which involves a man lying on his back while his female partner performs this splits whilst they are having intercourse, the man begins to spin the woman by her legs (at approx. 1278.3696 RPM) until the mans assistance is no longer required. This act is a gymnastic feat performed by only top professionals. It has a 98% mortality rate. There have only been four recorded occasions in which the act has resulted in no fatalities.
Guy 1: "I got to go to the doc's later"
Guy 2: "Why"
Guy 1: "Me and my girlfriend tried to do a Russian Helicopter"
Guy 2: "Ah, what injuries did you sustain"
Guy 1: "Well she died in a state of extreme pleasure and my dick fell off"
Guy 2: "Well that is to be expected"
Guy 1: "Yup... Nice Gilet"
Guy 2 "Cheers, man!"
Stands for 'Not A Fan'
When pronounced as a single word (naf) it is has the secondary yet almost synonymous meaning of something being 'lame' or generally not very good.
This acronym coincidentally spells 'Fan' backwards, adding further depth to it's meaning.
Because of these two notable coincidences, the word is entering common usage throughout the globe.
Person 1: 'Have you seen 'Avatar' yet?'
Person 2: 'Yes, but to be be honest I'm N.A.F'
Person 1: 'I'm N.A.F either, to be honest I thought it was naf'
Person 2: 'Agreed, in fact I'm the reverse of a fan, a naf, if you will'
Person 1: 'Oh, I will'