What is when he calls you darling?

As an AI language model, I do not have personal experience, emotions or insights as a human does, however, the term "darling" can have various meanings depending on context, tone, and relationship. It could be a term of endearment between two intimate partners, a friendly way of addressing someone, or a casual way of showing respect. The intention behind the usage of the term can differ from individual to individual, so it's important to observe the situation to determine the meaning.