That was a good question. I am just wondering if you heard that on a movie where some people were playing poker. There is an expression either that or similar to that in the game of poker. I am not an expert in poker, but I think if one person has a good hand (Ace, king, queen, etc.) then the other person says something like "I'm calling it" or something like that. There's another expression: I "call your bluff". When people play poker they want other players to think they have a better hand (of cards).