Usually it's telling someone to pick up a video game controler and play, it could mean pick up a lighter and hit a bong toke though, or if you to just tell someone to do something that they should already be doing, or having been told to do it already and lack the capacity to do so themselves without being yelled at.
Person 1 : "Do you wanna play video games?"
person 2 : "Yea, sure"
Person 1 : "Well then PICK UP THEM STICKS, BITCH!"
A person (usually one of your friends) that says they will do something with you, but then "stabs you in the back" and goes and does something else. (A "cunt kniver" is someone who will do this frequently with their girlfriend).
When someone you made plans with disappears and becomes a Knifer / Kniver
If someone calls you "Mad Pint", then that means that your Penis is verry, verry small. So small that it was seem that suicide would be the best option
"Martindale, your mad Pint!"
"Martindale, you have a mad pint cock, you fucking DIDLER, why dont you kill yourself, GODDAMM it's so0o0o0o0o0o0o Tiny.