People are always going to be people, my friend. They're weird and sometimes unpredictable. Don't overthink it, just do you and let him be him. If he's offensive and rude, keep your distance.

Didn't take you long to jump to racism 🥱 So you make fun of the guy and can't take it when it comes back? Now it's racism.

You gave literally no information about the conflict. So how is anyone supposed to comment on it?

Sometimes older people's medications have side effects that make them go off the rails. Or brain tumors. Or he could just be upset about something. Could be anything.

If he obviously seems offended, surely the first thing to do is apologize? Even just 'I'm sorry if I offended you'. Politeness is always the smart thing to try. Pushing him to justify why he's offended is just arrogance.

This tells us nothing about what he said, what you said, or the context. We have absolutely no idea what 'started getting offensive with me' means, or any other details. For what it's worth, I've met monsieurs and madames who are incredibly racist toward other Europeans. Expecting your condo neighbor to be the most open-minded, friendly chap toward a Punjabi Pakistani is asking a lot. If you truly come to hate him, carry a Spanish flag everywhere and wave it in his face next time you see him.