PUA: *Come back with strong body language; lean in slightly; get closer* Are you stalking me? (half grin/smirk; eye contact!)
HB: haha what! no!?
PUA: Your not!? See i was so convinced that you were stalking me; a bit flattered to be honest! I even told my little sister!
HB: *Laughs or Blushes*
The most important part here is how you "come back with strong body language" In fact, some girls might "move back" when you lean in, just a natural reflex. So before you lean in, make sure she is the kind of girl that is friendly/sociable. Not those that will blow you off immediately. Cold read her, it is to your advantage.
I mean if all goes well, the ideal response would be joking/flirting reply, "haha what! no!?" what if she gives you the "what a creep" look, even if you added the smirk.
I'm just giving you guys a possible worst case scenario, food for thought hah. Post a reply on what you guys would do if this really occurred when field-testing. I think it would be good to disqualify/neg her ASAP?

cheers