Demon Lord asked to marry her so I imagine that she never thought that her sister would be an acceptale alternative.
Hell probably has a whole lot of succubi running around that would be eager to please Mighty Demon Lord.
Seems to me that she realized when he said that he is lonely that a substitute would be acceptable.
suprise salvation from the priest, goes to show it doesn't matter how mad you are at them, you'll still be there to help them. back to demon lord, I know i suggested he be given a bangok haircut (look it up) and be screwed with his own member, but i can't help butt feel sorry for him; i bet alizee has many more tubes of lubricant after that