How can you gently tell someone that you honestly don't really give a damn about them anymore?

It's someone of the opposite sex. I think he's ugly, and now that I had a makeover and get better comments from people, I think I deserve better. He's also very immature and stupid. I think that he's more interested and in love with what I can offer him rather than what I am as a person. I think that I want to talk to alot of guys and flirt with them before finding the right one. Your thoughts?