It's a shock, feeling all of him against her. This has happened once before, but it wasn't quite her Clark, and the dynamic is different. Very different.

He's allowing her to cradle more of his weight, flesh tingling everywhere they touch. In some places, between her legs, for instance, there are fireworks. Eirene can't tell him how damn good he feels, because he's sucking on her tongue...

... so grinding her hips up against his is Plan B.