A fork of Rural Dictionary
When a man is urinatng in a public urinal on his own and he attempts to urinate an equal amount in each urinal by sidestepping like a crab while using hands to control urine distribution.
"I went into the urinals and there was no one there so I did a bit of crabbing" "My attempt at crabbing was ruined by someone coming into the toilets and spotting me mid-act, they gave me a pretty dodgy look"