Zoe was honestly touched at Wrath's offer and smiled a little, "That's really.." she didn't want to say nice or sweet or kind so switched tracks and said, "I really appreciate the offer but I know your sister means a lot to you." the Sin family was weird as hell but she'd seen enough and heard enough from Greed to know family came first.. only he was now making Zoe his family too. "I don't want me being Greed's girlfriend to cause problems between you two." it would put Wrath in a very awkward place because the excess Sins were very very volatile and Lust and Greed would most likely want Wrath to pick a side. And then there was the other thing Zoe was thinking... what if Wrath picked Lust's side. If Wrath was left out of the whole mess, then maybe, if Zoe survived, they could still be friends.