Movies
I’ll tell you what, you can get a good look at a t-bone by sticking your head up a bull’s ass, but I’d rather take the butcher’s word for it.
— Tommy • Tommy Boy

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The speaker says you could examine a t-bone closely by putting your head up a bull's rear end, but they would rather trust the butcher's word. It's a crude joke about not needing to verify everything firsthand: when someone knows the trade, taking their word is far more sensible than inspecting the source yourself.
Context reviewed