#polycule dynamics

Generally, neither of these pairs are going to immediately get along, mostly because of Jeanne, Vanitas, and Domi's possessive nature and the general trauma they've all been through.

Domi is especially affected by possessive issues. If Domi isn't in some sort of relationship with Noe, Vanitas has both the people she wanted and to make matters worse she has to share one of them while he keeps the other all to himself. Even if she has both, Domi doesn't have an immense amount of faith in Vanitas, especially because of his past, powers, and general existence. The happiness of the two people she cares about most in this world hinges on him and she absolutely hates it. Domi makes it her mission to remind him of that as frequently as possible, just to keep him in line.

Noe's simply happy to be here and to love this weird family he's found for himself. He's the most patient when it comes to solving disputes and strengthening platonic bonds with the rest of the polycule. Of course, he still gets jealous over sharing Vanitas with Jeanne, especially if he isn't allowed to drink from or mark Vanitas--that's what adds the strain on that metamour relationship. Still, he's the one most likely to be able to push past that and form a friendship with Jeanne. Still, managing one on one time and affection is key for this balance, and Vanitas won't always be the best at keeping this.

Speaking of Vanitas, he's genuinely the worst at this. He doesn't find himself deserving of love, and now he's got two people to love who also love him back. This is something that makes him incredibly territorial, as he's acutely aware of the danger having such a strong weak spot can put him in. He wants eyes on both of them at all times. This is mostly why my headcanon has Noe just in a relationship with Vanitas and Domi just in a relationship with Jeanne. There's no primary partners, but Noe and Domi act as anchor partners for the emotionally unstable center of this polycule. It does help Vanitas to know that if he doesn't have eyes on Jeanne, Domi does--it's something that allows him to focus on his time with Noe. He and Domi don't get along at all--it's more like a custody agreement that just allows him to (sometimes) sleep at night.