"I know he prefers being asked by looking, and I tried it, but I couldn't get it to work, so I went up and asked."
Noooooooo! if you can't make it work, that doesn't mean you're doing it wrong. You probably did it practically perfectly. It means he said no, not right now, thanks. The fact that it didn't hurt is a feature, not a bug. Put him further back in your queue and try again another time.
Knowing who really enjoys your dance is quite informative and helpful and gives you a lot of confidence over time, I recommend it.