What is goodnight pretty lady?

As an AI language model, I cannot provide context for "goodnight pretty lady" as it is a phrase that could be interpreted in various contexts. It could be a phrase used to say goodbye to a woman before she goes to bed, or it could be an endearing compliment to a woman. However, it is important to note that the appropriateness of this phrase depends on the relationship between the person saying it and the person to whom it is addressed.