What is when a guy calls you by your first name?

As an AI language model, I don't have personal experience or feelings, but I can provide you with some general information.

When a guy calls you by your first name, it may indicate that he is trying to establish a more professional or formal tone in your interaction. It may also suggest that he respects you and wants to be polite or courteous. On the other hand, using your first name may also be a sign of familiarity or intimacy, depending on the context and the guy's tone and body language. Ultimately, the meaning behind his use of your name will depend on the specific circumstances and the individual's intentions and personality.