Being choked makes me uncomfortable

I was a guest in the home of a long-term friend. We both live alone and are not in an LTR with an SO. When we were walking on a busy street he stayed behind me and--at one point--grabbed me from behind and pushed me to the side. I was startled and freaking out because when I'm in a city I don't like being touched (especially from behind). He said someone was trying to pass me and I was 'weaving' left and right.
Later that evening I was on the computer (as I am now) and he came up behind me, put his hands on my neck and began to squeeze. All the while, he was saying, "I'm sorry."
That time I really got weirded out. "Please don't choke me while you say you're sorry. In my culture that sends a very negative message," was what I told him as I grabbed his hands off me.
"I was just massaging you," he said.
I am reminded of the number of times he also says off-the-wall things and follows them with, "I'm just kidding!"
Sometimes I wonder what goes on in the minds of those who are needy. I mean, I'm sure each of us is needy in his own way and some express their needs with greater verbal clarity. I'm better at identifying when someone makes me uncomfortable.
I like to think of myself as the guest who says, "You won't even know I'm here." I guess my vision/fantasy of what that means is different from others. For example, while he was outside on his balcony smoking a Marlboro, I was washing two sinks' worth of dishes, bowls, and utensils that he had piled. He didn't like that I was cleaning something that he was too depressed to work with. He also claimed to be overly sensitive to the light (while outside?).
We only see one another once a year. Maybe I might have to consider visiting someone else next time.