His hands stroked the sides of her full breasts, slowly rolling his hips, before he silenced her with a deep kiss, before biting her tongue. He simply enjoyed her for a moment, before pulling his mouth free, his fingers pinching and pulling her nipples. "It would involve permanently binding you to me. You would never be far from me, able to tap my power to supplement your own, and most of my other advantages would also become at least somewhat available for you to use, and even if you are somehow defeated and destroyed, I could immediately resurrect you next to me. But you would be literally linked to my soul, unable to actively do me and mine harm. And the binding is, as I said earlier, permanent. Eternity is a long time, my gorgeous marilith, hence why I offered and still do the chance to decide."