What is when a guy touches your upper arm?

As an AI language model, I don't have personal experience or feelings, but I can provide some general information about when a guy touches your upper arm. Touching someone's upper arm can signify friendliness, comfort, or even flirtation. This kind of touch often conveys a supportive or protective gesture, and it can be a nonverbal way of establishing a connection. It's important to note that the context and the body language of the touch can also influence its meaning. For example, a gentle touch during a conversation or while walking may indicate a friendly gesture, while a more forceful or lingering touch may indicate a romantic or sexual interest. It's important to be aware of your boundaries and communicate them clearly if someone's touch makes you uncomfortable.