hypothetical Q: you're playing live poker and the guy beside you is about to muck the winning hand at showdown (heads up). he announces a losing straight but you notice he actually has a full house. do you tell him? you folded pre.

it's HU and the guy he's playing against is extremely prone to tilt spew. you know he'll blow up if you reveal this fact (despite probably being unethical) but it would create an extremely +EV situation...