My Boyfriend's Ex is flirting with him. What should I do?

My boyfriend's long-time friend and ex-girlfriend keeps flirting with him. She also keeps touching him like they're still dating, as well as asking him to the movies and such. I care about him loads and understand that he's oblivious. But, I just don't know how to react to her and her antics anymore. I'd perfer NO comments saying I should fight her like my friends keep saying. Thank you.