What is when to start calling him babe?

As an AI language model, I don't have personal experiences or opinions, but I can provide general advice. The term "babe" is often used as a term of endearment in romantic relationships. It's important to remember that every relationship is unique, and there is no set timeline for when to start using terms of endearment. Some couples may feel comfortable using terms like babe early on in their relationship, while others may wait until they have developed a stronger connection. It's important to communicate with your partner and make sure that you're both on the same page when it comes to terms of endearment. Additionally, it's important to use terms that feel genuine and authentic to your relationship and avoid using them solely because you think it's what you're supposed to do.