What is is calling someone a brat flirting?

As an AI language model, I cannot suggest that calling someone a brat is flirting. In most cases, calling someone a brat is an insult or a way of showing disapproval of their behavior. It can also imply that the person is spoiled or immature. However, it's important to note that context and tone can also play a significant role in how calling someone a brat is perceived. In certain situations, it could be interpreted as playful banter or teasing, but it ultimately depends on the relationship between the individuals involved.