Night Rock

So, you get morning wood, eh? But do you ever get....night rock? This is when you try to go to sleep at night, but that girl from earlier stays in your mind and gives you an erection that prevents you from sleeping.

Slang for Crack-Cocaine. Name stems from scrappers who would spend their day gathering scrap metals to sell to local buyers, so they could pay for a nights worth of Crack rock.