Absurd stunt involving David Blaine hanging upside-down above a NYC ice-rink for a couple of minutes, duly extended to mean any publicity-grabbing gig exposing the protagonist as a complete "twatdangle".
From Old English "Twattendang", from the Viking "Twtdnglersk", meaning to hang from the rigging of a longship in an attempt to impress your shipmates.
"Hey, did you see the upside-down David Blain thing? That was like so cool."
"Nah, the guy came down after two minutes for a piss. It was a total twatdangle."