The friend who accepts everyone's unwanted Gherkins at McDonalds.
Tom: "I'll have that if you don't want it dude? I know you don't like them"
Joe: "C'mon man, quit your Gherkin Lurkin' and order something"
A cat just lurkin' about spying on you (in general) or especially whilst on the toilet or in the shower.....
A weird person watching you....or whom you notice is about looking suss
Omg, I feel like I'm being watched....
Oh phew, it's just my cat being a lurkin' gherkin!
That weirdo over there is just lurkin' like a gherkin