Girls are awkward and creepy?

I was in a party today then this girl came up to me while i was alone watching the gold cup soccer final , and she started asking many questions about me she told me she was 13yrs old and I'm 16 so .... I just replied normally lil bit annoyed since she kept asking question .. So finally it hit the point were she started getting weird telling me how cute i was and stuff so she stood up and just started kissing me lip to lip .. I just let it happent tbh she wasnt bad at all we were same height lol .. Weird or what? Was this normal? Did I do bad?