I smell
You know someone is lying and you're not going to let them get away with it. You're like 'I know what you did, and I'm not in the mood to play games.'
I said 'I sense a lie' when my friend said he didn't eat my sandwich.
I said 'I sense a lie' when my brother said he didn't steal my game.
I said 'I sense a lie' when my mom said she didn't eat the last slice of cake.