Third dance, Sirius and Narcissa
Sirius saw no reason to shelter Narcissa from his memory; as far as he was concerned, Narcissa had played her part in the war. Her actions might be innocent enough now, her intentions and priorities changed. But she had enabled the destruction of the first war. In Sirius' eyes, her inaction condemned her, even if he believed that now she behaved differently.
"Standing in the rubble of the house at Godric's Holow, I'd found James and Lily. I believed Harry to be dead too," he said in a matter-of-fact tone. Sirius didn't expect to elicit and feeling from her, and he was surprised by his own calm explanation. His eyes were a little harder than previously, the line of his jaw set tighter, but any wave of anger or sadness was kept firmly down. A reaction was often a victiory, and he hadn't forgotten Narcissa's oft scornful and even malicious tones. He was prepared to be pleasant, but he wasn't going to hand over an opportunity for sniping on a platter. Of course, this was an older, possibly softer Narcissa but he wasn't taking any chances.
Her tone when she spoke of Teddy shouldn't have surprised him. If Andi and Narcissa were speaking now, clearly it couldn't be with Narcissa openly disapproving of Teddy's existence. Andi was very protective of Teddy, and understandably so. Sirius imagined that during the war the child had needed careful protection - he was an example of everything Voldemort had disliked.