I have always been unclear as to why Moe ASKS if Mike thinks he is skimming off the top.
Mike says to Moe 'your casino loses money, maybe we can do better.' to which Moe replies w/ a question 'you think i'm skimming off the top, Mike?....' Why does he ask Mike this question if skimming is such a common practice?

(Of course Mike's response of 'your unlucky' to the career gambler Moe is one of the funnier moments of the entire trilogy , although Moe did not find it too funny. )