Mettaton nods promptly.

"Yes, I know you're content now but what if you're not content later? What if, a few years down the line, you feel like being trapped here isn't want you want? You'd have no choice but to accept your fate! I can't let my favorite cousin be bound to the laws of life and death if I can give them an out!"

This is all so casual to him. He has no idea how out of touch he really is.