Get some tricks for isolation.
once isolated and the girl is comfortable in it. Calibrate and escalate (physically)
Use mystery method line if nothing else...
YOU = Do you wanna kiss me?
HER = NO (for cases with Anything other than NO means you can try it, and can claim she did not say no if she reacts offended)
YOU = I did not say you could... it just looked like you wanted to...
and ward it off like a joke (thus preserving your status)
From kissing i am sure you can take things further yourself.
-- Jack