Hello, I've seen "I'm calling bullshit" used a lot in forums discussions(not Wordreference, to be exact, but other forums) and though I never aksed for its meaning, I kind of get what it means and when to use it. I just need a confirmation if my understanding is correct. So, "I'm calling bullshit" is used to point out inconsistency in someone's statement, or something you think is untrue based on personal experience and usually followed by your own opinion. Here's my example: - ABC restaurant is so good. The food is delicious and very cheap. - I'm calling billshit. I've eaten there before and it was terrible. Is this how one would use it? One more thing, I think this phrase sounds very American though not sure why.