fail the smell test

To be morally questionable, unacceptable, or untrustworthy. The new pro-drilling bill that's being put through Congress certainly fails the smell test, and many are suspicious that Big Oil has been responsible for its inception. He's a lawyer—why are you surprised that he's issuing statements that fail the smell test? A: "Rick said he was home last night at 9:00. Wait, you think that fails the smell test?" B: "Yeah, because Rick was out with me at 9:00 last night!"