What is Sir-fingus?
1.
The growth in between a fat mans balls and his bum hole.
1-
Terry: Oh man, that's fuckin sick!
Nathaniel: What?
Joseph: Shit Nat, your sir-fingus is hanging out.
Nathaniel (embarassed): You guys man...
2-
Bob walks out of his front door naked.
Next door neighbour: "Hey Bob, ur sir-fingus is flopping around."
Bob: "yeh, cheers mate"
See