British: ref to gay/anal sex without use of lubricants. More commonly used to mean being got the better of in an extreme sense.
Alternatively to mean a desire to have sex with someone you don't actually like.
Paul was totally dry bummed at pool yesterday.
I know you hate her, but I bet you'd dry bum her if you got the chance.
Hammering someone's asshole without the use of lube. Commonly a pleasurebale experience to the hardcore butt fucker but now creeping into the hetro hardcore lingo
I'd dry bum her mate;