Horseface
It feels like there's a really good movie hidden somewhere in here, but perhaps not a comedy.
As far as the comedy goes, its biggest obstacle is Brad Pitt. I remember seeing another comedy with him in it, and I remember him being not particularly good. This time around it's even worse, and it's clear to me that the man doesn't have a funny bone at all.
There's plenty of comedic material in the script, as delivered by the supporting cast, but to be frank, Brad Pitt is simply terrible. I don't remember having seen him this poor, ever, and I'm really quite a fan of him. Why he fails so terribly to be funny, I'm not sure. Perhaps he lacks the ability to do self-ridicule, perhaps he tries too hard, perhaps he doesn't really get humour in ...