Damn right, his will was the one driving it. If he told her to stab yourself with the Winchester's demon-killing knife, she'd have no choice but to do so. Not that he intends to waste her like that.

His hips snap forwards even through his next orgasm, Gabriel already seeking out his next one. He was almost done with this portion of things. He might give her a little time to recover after this. Maybe. In a fashion.