you said to yourself "cool, I might get laid"
is this the way you would approach a job interview? Like, hm, they might like me, i'll let them do all the work and if they don't like me then I have the worst luck ever, and i can't believe they hired that other guy.
No, you'd find out more about the company, look your best, and 'flirt' with the interviewee...not flirt in that sence, but i mean, a little bit of sucking up, you know, whatever you can do impress the interviewee.
Maybe you are taking this girl too lightly.... like, if you really liked her, you would have made more of an effort to be more intimate with her (or sexual). I don't know how you acted, because you didn't describe it...all you said was how she was acting "cuddling and flirty", but how were you acting?
So maybe you don't like her very much anyway, you think of her as so-so, in which case...why does it matter?!?
you've got to tell a girl how you feel, she can't read your mind.
If youve given this girl all your effort then I take this back.