You're pissing up the wrong tree.

你可招惹错人了。

I mean, there's some joke in there about organising a piss up at a non-alc competition, but I'm not quite sure what the joke is.

我的意思是， 那里有一些关于在非 alc 比赛中组织小便的笑话，但我不太确定这个笑话是什么。