Called magpies because if they have gotten it once, they'll expect it again, and again, regardless of who it is.
Magpie : 'Ey man, u gutta spare smoke i can borrow??
Person 1 : No, go away
Magpie : Please man, i havent had one all day...please....
Person 1 : I saw you smoking 10 minutes ago, fuck off
Person 2 : GO AWAY you fucking mapie
Magpie : Pleeaase man, i'll pay you back