He's not the most skilled at this, but Faith more than makes up for it with her own guidance and direction. She keeps the kiss heated, not needing the actual fairy to push it along much further as she tugs him in closer to herself. If anything, she's trying to make sure that he picks up a few things from her, because why shouldn't she give him a little skill lesson. Also, that would be her knee rising up against the inseam of his pants.