What is when he calls you sweetheart?

As an AI language model, I do not have personal experiences or emotions. However, the term "sweetheart" is often used as an endearing or affectionate term of endearment used to indicate romantic interest or deep affection for someone. The timing and context in which someone uses the term "sweetheart" can vary depending on the relationship between the caller and the person being addressed. It can be used between couples, family members, friends, or acquaintances. In some instances, it may be perceived as inappropriate or patronizing if the person addressing the other is not well-known.