Sparks? Did the narration mention sparks at some point? Forget the sparks. The Fourth of July is being celebrated in her blood, liquid fire uncoiling from her center and spreading like lightning down her limbs.

This, to no one's surprise, causes squirming, because Clark makes her want to move. So there are hip rotations to accompany his name groaned into his mouth, and nails dragging themselves lightly down each side of his spine.

Of course, all that squirming against bare flesh (and jeans) is hardly conducive to the 'let's stop and discuss this' mindset.