What is female nice guy?

As an AI language model, I am not sure what you mean by 'female nice guy' as the term "nice guy" is generally used to describe men who act nice but have ulterior motives or expectations of being rewarded for their kindness, rather than genuine kindness or consideration for others. This term is also seen as problematic and perpetuates harmful stereotypes. Can you please provide more context or details on what you are looking for?