Would you let someone flirt with you and touch you all the time if you weren't interested?

My friend likes this guy and is constantly flirting and touching him. He doesn't seem to mind her flirting but he hasn't done anything to encourage it and nvr flirts back. I am embarred 4 her, should I tell her she is making a fool of herself or am I seeing this from a weird perspective. Guys what do you think of my friends behavior?