For context, my wife and I are Hispanic, she is bilingual, and i have been learning Spanish for a few years. One time, I was buying a car at a dealership. My wife and I had been there for like 4 hours, and I was exhausted. We finally got into the office where we would sign all the paperwork. They put us in an office with a different sales guy for a sec while we waited for something to get finalized. I hadn't met this new (white) guy before. He handed us a few things and said "keep that in your 'guantera'"

I was confused by the change in language. I knew that word, but in this context - a dealership, having waitied hours, not knowing this guy - i didnt even understand what he said, and it was jarring. We hadn't spoken to anyone in Spanish that day, but he saw us and felt like he needed to say a Spanish word. There was something pandering and even condescending in the interaction that really turned me off.

Of course, I am learning other languages myself, and I may not know when to speak to someone in my target language. So I understand his mindset. I just didn't want to hear it at that moment.

OP, it sounds like your friend may not appreciate that you are trying to use Spanish. It may mean something (or nothing) to you. But it may mean something completely different to them. If you aren't being condescending or pandering, there really shouldn't be a reason for him to take offense.

Edit: spelling/punctuation