A Rusty Goblet of Fire is when your having anal sex with a girl/guy and right when your about to cum you stick it in their mouth then grab their hair and yank their head back causing them to gargle the cum in mouth.

*** You must be a redhead (firecrotch) and be having butt sex in order for this to be considered the Rusty Goblet of Fire.
Gee wiz Ron, I think I got tetanus from that Rusty Goblet of Fire you gave me last night.
by Harry Ilikeitinthebut July 7, 2010
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