<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
My 30 year old girlfriend likes to cosplay as a junior high school student with a short skirt. I enjoy it.
<|assistant|>
That's great that both of you enjoy it! If she is comfortable with it, there is nothing wrong with it. It is a form of expression and can even be seen as a way of celebrating her youthfulness. As long as both of you are comfortable with it and it is not being done in a sexual or demeaning manner, there should be no problem.