When someone's listening to hard rock/heavy metal reaches to an epic level, normal headbanging can't coupe with the sheer power of it. That's when windmilling comes to play.
Goes great if the person has long hair and a brain as strong an Air Force pilot's ('cause it'll gives you some fucking powerful headaches if you're not careful).
Windmill headbanging, harder to do but much more fun to watch than normal headbanging.
"Fuck, man! Listening to Amon Amarth, Morbid Angel and Cannibal Corpse is giving me the urge to windmill my head off!"
When you wear a large headband around your waist and her neck as she is giving you oral. The elastic band acts as a rubber band effect, so when she pulls back it forces her back down. Possibly causing her to deep throat.
Dan was at the arena, Winston standing behind him talking to Carl. After several minutes, Dan realized that Winston's junk was resting comfortably on Dan' head. Needless to day, Dan was unimpressed. Winston headbagged Dan. Prime example of a headbagging!