i smell bullshit - when someone is talking trash and you know they're full of i

when someone is talking trash and you know they're full of it

'I could beat you in a race any day.' I smell bullshit and I'm already out of breath.

'You didn't even study for the quiz.' I smell bullshit and I'm still getting an A.

'I didn't cheat on the math test.' I smell bullshit and I'm holding the calculator.