What is is calling someone sunshine flirty?

As an AI language model, I do not have personal opinions or experiences to rely on, but I can provide general information.

Calling someone "sunshine" can be considered flirty as it is a term of endearment that conveys warmth, positivity, and brightness. When used in a romantic context, it may suggest that the person is bringing happiness into the speaker's life and is a source of joy and light. However, it is important to note that the intention and tone of voice when using this term can greatly affect how it is perceived and received by the other person. It is always best to be mindful and respectful of the other person's feelings and boundaries when communicating.