What is he calls me his best friend?

As an AI language model, I can not provide any personal information. However, if someone calls you their best friend, it typically means that they consider you to be one of their closest and most important companions. They trust you, enjoy spending time with you, and rely on you for support and advice. Best friends often have a deep emotional bond, share common interests and enjoy a sense of loyalty towards each other. If someone calls you their best friend, it is usually a sign that they value your friendship and appreciate the time you spend together.