Inspired wholly by thinking about how damn well-planned Inutaisho apparently had his sons' lives, plus a line from Harry Potter and the Order of the Phoenix where Hermione accuses Harry of having a "saving-people-thing", which we all know Sesshoumaru totally has.
"Ah, so, why are you giving me this again?" she asked, examining the stone once again with a thin eyebrow raised.
The dog demon rolled his eyes back at her, and gripped his hands behind his back. "I've explained it six times already, have you been rendered stupid recently?" he shot back.
Sticking out her lower lip, she turned up her nose and at him with a tiny 'hmph'. "Why should I help you with this? You've been out gallivanting with humans, it's not fair."
Grumbling to himself, he crossed his arms. "There may come a time when your son needs assistance with his sword. He will suffer, I'm afraid. But it's what's best for him – you know how that boy is," he said, and he caught her nodding in agreement for a split second as she broke character. "I don't know if I'll live to see the day, but I'm sure you'll live long enough to terrorize him well into adulthood, so I'm trusting you with this."
"You have oddly specific concerns about your son's future, you know," she said. "Why will he need help with his sword, precisely?"
Oh, that's a tough one to explain, he thought. "I'm kind of worried he might develop a…well, a saving-people-thing."
"I can see where you're coming from. We'll have to take him down a peg if it comes to that," she agreed serenely, folding her hands in her lap.
"I'm glad we can agree on something for once," he said.
She thought she should have pretended to refuse.
"Though, I don't know how we can discourage him from gravitating towards obnoxious, loud-mouthed women," he added with a smirk and a meaningful glance at the woman before him.
"I'm ignoring that insult," she said pointedly.
Miles away, a young Sesshoumaru sneezed.