When someone does something that aggravates us, it's in our nature to ask them why. That can make things better or worse, depending on how you go about it. If you want to avoid sounding passive aggressive, you need to make your curiosity obvious.
When you're clueless about a topic, asking questions about it can make you feel dumb. However, despite how you feel, asking good questions actually makes you seem smarter. This video breaks down research that supports this very concept.