Guys - I'm confused. Need your opinion/advice?

A guy gets jumpy if you touch him especially on accident, even sometimes scoots his chair away afterward. BUT sometimes when he sees you, his leg is next to yours and he taps you a lot or rests his hand on your arm. A few months ago, he use to be very touchy even put his hand on my lower back when he left or touched me in some sort of way. But it just stopped and he's jumpy like I said. He only does it if he has had 2-3 beers - no, he's not drunk. What gives?