It takes time because she is worried she might not get along with Tiamat.

You go up to her. Guess you have a thing for powerful demon women. She's not as powerful as Tiamat's true form but there are more demons weaker then her then there are demons stronger then her. You should be careful not to anger her. You'll be in for a tough fight.

You enter a pyramid. The inside is filled with roses. You see her at her desk writing something. "Hello." She turns around and faces you. "Why do you enter the Pharaohs tomb mortal?" You clear your throat. "Well, I'm traveling the multiverse in search of the most beautiful law aligned demon to add to my harem." She nods, no question in her mind you find her the most beautiful demon is existence. Not even considering you mean shes the hottest law aligned demon but not the hottest demon of all. She thinks you mean shes the hottest demon and she happens to be law.

"Do you have any other woman in your harem?" You show her a picture of Tiamat. "So far just her. I actually only wanted 1 lover at first but she really wants me to build a harem and to share them with her. So if you do agree to be 1 of my lovers, you'll have to get along with her and have sex with her every now and then." She licks her lips looking at Tiamat, but then she thinks of something. "You specifically want a law aligned demon because you want variety in your harem and shes chaos or neutral, am I correct?" You nod. "Absolutely correct. She's chaos." She thinks for a moment. "And you're neutral?" You shake your head. "I don't really care about alignment. I just want to be loved and have losts of sex with beutiful woman."

She sighs. "I'm not saying no yet just because I find you interesting. However your current lovers beliefs are the exact opposite of mine. I'd worry we'd fight all the time if we ended up living together." You shrug. "Just because you're law aligned doesn't mean you fallow every single belief of a law and just because Tiamat is chaos doesn't mean she fallows every belief in chaos."

She nods. "True. If I could take Yahweh's thrown I would. Though all law demons believe its worth giving up all freeding to live a long, peaceful life while all chaos demons believe its worth risking death at any moment for absolute freedom. Thats a fact. So no matter what me and your Tiamat are garenteed to have a big difference in our beliefs." You counter her argument. "So do you only want to talk to clones of yourself with the exact same minds? I think that would be incredibly boring. People having different beliefs then me is what makes talking to people so fun. If there beliefs are too far from mine, I'd probably not want to talk to them anymore but I'd never refuse to try to become friends with someone until Ive spoken too them first."

Cleopatra thinks about your words. "How about this? If you manage to seduce me, I'll become your lover and bare your child. I'll remain your lover until you decide its time for me to meet your current lover. If I enjoy her company, then I'll stay your lover and we can be 1 big happy family. However if I don't like her, you'll have to choose. Me, or her." It would really suck for you to fall on love with Cleopatra only to break up with her, but having her and Tiamat is worth the wrisk. "I agree to your terms."

She walks with you to the royal dining hall. She has her servants make food for the both of you.