What happens if you just smack a girl’s that’s into you butt?

That’s obviously into you but you haven’t escalated. I feel like it would skip the BS.

To be more specific, there’s this girl in my chemistry class who has a crush on me, I haven’t spoke to her but she’s staring at me and when I look back and check her out she smiles and gets shy. I was thinking I should just smack her butt or something.