What is the proper/most common spelling of this word? Is there one? I searched online and there seems to be several opinions. I know I've read the word before but can't remember where.
it's slang so it doesn't really matter but I would go with the spelling you have used or fricking depending on how the particular character saying it or thinking it speaks . for exmaple you may have a mobster type character say "Frickin' A!" where as someone more upper class trying to swear may pronounce it properly as in "That Fricking hurt!" because they would pronounce the G on the ING