He has been telling everyone I fancie him because my best friend rejected him?

I have a massive crush on a boy in my class but he has a massive crush on my best friend, she knows I like him and she knows he likes her but she doesn't like him back because she likes other boys and she hates him. But she has got a flirty personality and he asked her out today but she said no. And he has been telling everyone that the reason she said no is because her best friend, me, fancies him. I look really desperate. I need to talk to him tommorow about it , what should I say to him? And I know "you can't make anyone like you if they like someone else" I know so please don't put that. Thank you xxxxxx