Hairy needles is when your pubic hair gets caught in the foreskin of your penis causing your '3 millimeter defeater' to be in a state of uncomfortable cock torture.
Usually a sign that you should shave your pubes.
Homie1: Bro, is anyone coming, i need to sort out my 'hairy needles'
Homie2: your good feller, ill tell you if anyone's coming
Homie3: i hate 'hairy needles', its super uncomfortable.