The act of cutting in line while stepping sideways in the manner of a crab like crustacean this can also be used to describe the actions of the animal its self
.1 Man that fucker just side skrimpt us!
.2 Dude that crab is side skrimping like a mother fucker! Look at how fast he is! LOOK AT EM!
Prisoner 1..What are you banged up for?
Prisoner2.. I got caught pussy scrumping, I got 6 years, its my 2nd time for rape
Prisoner 1.. You nasty prick, I'm going ass scrumping tonight, see you then