Green’s Dictionary of Slang

a sodomite; a pederast.

1967		Partridge DSUE (7 edn).
1975		Ribald (Sydney) 29 May 10/5: Titles included ‘Tongue Teacher’; ‘The Bumfuckers’; ‘The House of the Golden Showers’.
2000		M. Manning Get Your Cock Out 89: Bumfucker bumfucker bumfucker yeah alright!