Idk what to do , can you help me?

There's this girl that likes me but I'm bi and more into boys then girls. I don't want to break her heart but I also don't want her, not cuz she's not pretty or anything, she's beautiful but I'm not really all that into her and she keeps clinging on to me which makes it hard to flirt with cute, hot boys. Can someone please tell me how to fix this problem?