Oh, Ollie. Who the hell let you near teenagers?
It took me several minutes of consideration before I worked out that "Do the big funnies at him" probably meant "make fun of him". Without context I never would've gotten it.
I always forget just how very obvious Roy is here. "Gee, Green Arrow, what could make an upstanding young man turn to drugs? Well, I dunno, maybe if this upstanding young man was somebody's sidekick, say, and their mentor kept ditching him to go hang out with his boyfriend, for instance, maybe they'd turn to heroin to kill the loneliness and daddy issues. Hypothetically. By the way, our neighborhood's been hit with grafitti taggers again- somebody painted I'm on drugs, for God's sake, what the hell do I have to do to make you remember I exist?! right across our front door."
...At least it appears to have occurred to Ollie to feel a little weird about, y'know, having had no idea where the teenager he's responsible for even is. For a month. Without having done anything about it. (Around how old is Roy here, anyway, seventeenish? I would say eighteen, since he heads off on his own at the end with no objection from anyone, but ha, like Ollie would care, and Dinah didn't know his real name, did she, so she probably wouldn't know his age either.)