She looks like their mother when she ties her hair up like that.
She looks like their mother when she paints her lips in just that shade.
She looks like her mother and he realizes that he can't quite resist that.
Zuko notices these things in the faintest glimpses. And he wonders what they mean. He wonders just how like their mother Azula truly is. And in some ways it makes him uncomfortable. When his hand brushes hers…when their lips meet, a part of him tenses and cringes. Because sometimes when she wears her hair a certain way, cloths her body in certain outfits, does her makeup in certain shades, he could swear he's kissing his mother.
He crossed a lot of boundaries already, just by being with Azula. The only reason he got away with it was through claims of wishing to keep the bloodline pure. But just the idea of being with his mother was sickening to him.
Sickening enough that when Azula particularly resembled their mother he would push her away and keep her at arm's length until she started to look less like Ursa and more like Azula again. And it hurt him in the worst way to see her look so hurt…and then eventually angry with him for casting her aside with no apparent cause. She never did handle rejection well and would usually put her walls up in return—not speaking to him for days or a little over a week even after he came back to her.
At first Azula had placed a lot of it on herself, wondering what she had done to him to make him so angry. What she had done to earn his cold shoulder. She had asked him why he would push her away. Zuko couldn't bring himself to vocalize the embarrassing truth. So eventually Azula shifted the blame to where it belonged.
With him.
He deserved it, he knew. He'd much rather see her mad at him than frustrated with herself for no reason. It hurt to see her berating herself. And it killed him to know that he had been too much of a wimp to tell her the truth. But how does one even go about confessing the type of discomfort he had.
What seemed to make matters worse was that there were times when she'd act more like her mother than she realized, than she ever wanted to especially given their history. The way Azula would comfort and encourage him in particular reminded him of their mother. How she would tell him that Ozai's opinions no logger mattered and questioned if they ever should have.
How could he possibly tell her so? Without a doubt the princess would be less than thrilled to hear that she was like Ursa. He was damned if he did and damned if he didn't. Zuko hunched over pressing his elbows to the desktop and his palms to his eyes. What a frustrating situation. He looked up at Azula who brushed right past him, it had been three days since he had pushed her way and three more since she decided she still wasn't going to talk to him when he decided his discomfort was gone.
He was going to lose Azula. And because he couldn't seem to separate she and their mother. He bit the inside of his lip. He was going to tell her. Even if the revelation made her angrier than secrets. At least he could say he tried.
At least if he only earned her scorn for it, he'd clearly be able to separate Azula from Ursa.