It means you are not to be trusted and you appear as a friend but once they come up around you or have something you want you backdoor them for it doesn't matter who it isð
"Don't trust Kev he's going to slime you"
It means your above the slimes you willing to slime anybody out or slimed out a closed friend before and will do it again without feeling remorse
I heard mat back stabbed Jay for those new jordans
Jay knew Mat was so slime he dum for being around him