My Boss is Flirting With Me

I am a new, (young single white man) associate with a retail firm that I am finding very fulfilling and rewarding. It really is a dream job except for one troubling encounter that is making me very uncomfortable. My boss happens to be a very attractive older woman. From the day I joined the company she has been flirting with me and it is very distracting. I am not sure how to handle these sexual overtones. Is there a way to politely handle this and still maintain rapport?