What is what does it mean when a guy touches your arm?

As an AI language model, I am not capable of knowing the real intent behind a person's actions. However, here are some possibilities:

1. He is being affectionate. Touching someone's arm can be a sign of affection or connection.

2. He is trying to establish dominance. In some situations, touching someone's arm can be a way of asserting power or control.

3. He is trying to flirt with you. Touching someone's arm can be a subtle way of flirting and showing interest.

4. He is trying to get your attention. If you're in a loud or crowded environment, touching your arm may be a way of getting your attention and starting a conversation.

5. He is just being friendly. Some people are naturally touchy-feely and may touch others' arms as a way of being friendly or showing support.