Working at a front desk with two co-workers who were related. They are speaking Spanish and one of them is talking about how she thinks I'm weird/act too professional all the time". She then asks "where is the stapler?" in Spanish. I picked up the stapler and without looking at her I extend my arm to pass it. She then asks if I speak Spanish and understood the whole conversation. I told her I speak fluent Italian and took Spanish classes in school.
Another story. At the mall eating McDonald's when I was a teenager. Bunch of old Italian guys hanging around the food court and one asks "how can he eat that shit?" In italian, While looking at me. I look up and stare at him. I say "because I'm really hungry" in Italian. All his buddies started laughing.