Abaddon glanced down at the angel's hand, surprised that she would so readily touch him. She had seemed so repulsed not too long ago and--

His surprised thoughts stopped dead as her lips found his. If he had been shocked before, it was nothing compared to this. Along with shock, came a sudden feeling of what he could only imagine redemption to feel like. And it hurt. It tore through him and left no area unexplored, extending pure white tendrils everywhere. 

Abaddon kept his lips on Camael's for a multitude of reasons; one of them to prevent his crying out in pain.