Bulls are the most tolerant sign and are patient and understanding enough to listen to just about anything... with four major exceptions.
Here are four phrases that get under a Bull's skin enough that they might just snap back with what they are really thinking (I added this part for fun).
"Hurry up!" (No, you slow down! I want this done right...)
"It's too expensive." (So? It's better to have quality over quantity. And I'm worth it!)
"No." (Ummmm, the right answer is YES.)
"Let's try something new." (Why? This works so well the way we do it now!)