Peter, wary of his target, follows her with the intent of gathering information. She fascinates him, even as he very readily realizes this is a very dangerous situation.
Note to self... don't let her kiss me.
As he approaches her on the dancefloor, he glances around at the mass of people, listens to the overwhelming sensory assault of the music, realizes he had been texting his companions because it was entirely too difficult to be heard. He mutters, "Enclosed space, no one can hear you scream..."
With that, he moves towards her.
If she's stopping here, Peter will actually move behind her, putting his hands on her hips. This, he feels, will accomplish a few things. First, it gives the impression of club business as usual. Second, it puts him in a superior tactical position... he can talk into her ear, she will have to speak up but Peter can try to make sure those lips don't get close enough to actually make contact (who knows how she really focuses whatever spiritual power she has, but if you go by mythology, a kiss would be a reasonable method). Thirdly, if need be, he already has his hands on her... it would be easy and about as discreet as possible for claws to dig into her midsection with a firm grip.