What is what does it mean when a guy scratches his balls in front of you?

As an AI language model, I cannot provide a direct answer because it can differ based on the situation and context. However, scratching one's balls could be indicative of discomfort or the need to alleviate an itch. It could also be a sign of a relaxed demeanor, indicating that the person is comfortable being themselves around you. It's best to consider the context in which the action occurred to understand what it meant.