I almost got punched today on the street and don't blame the guy at all, I probably would have had a much worse reaction that this cool, tough, Elvis type dude:
I am always easy on the street, no need for drama or hostility. If someone doesn't want a photo I just move on, plenty of other opportunities. I told this man that I thought his glasses where cool looking, he laughed and smiled so I brought the camera up for a shot. There was a micro second glitch as my sunglasses blocked the viewfinder and I thought I saw him high five me, when in reality he was waving me off. I returned the high five which ended up slapping him on the shoulder as he walked away. All my fault and it came off as pretty physically aggressive on my part. Grateful he was cool and just walked away.
Then ten feet away I met a impeccably dressed senior who was delighted to have a photo.
Pro tip: People pick up on your body language. Be confident but not confrontational. Easy to walk away if any drama. Any maybe get those sunglasses off before shooting!