"Not the part that made you two happy," he said, then looked at Zumi, who'd stayed uncharacteristically quiet so far. She looked emotionally exhausted, though he could see in her eyes that she wanted to argue, but- whether from that exhaustion, or because she was letting Yammo take the lead -she wasn't. He wasn't sure which. "You weren't a mistake."
At her visible relief, he gave them both a rueful smile, and a shake of his head accompanied by a vague hand motion and a shrug. "It's just the circumstances. Even if there'd ever been anything said or done back then, my amnesia made it a moot point, and that was nobody's fault."
He tilted back just enough to look up at the ceiling. "So the next question is, what's the plan? Zelda still needs help that I can't give her, and don't know who else can, and I can't shake the feeling that it would make her miserable to have Zumi that much a part of her life if she knew that my part in Zumi's pregnancy wasn't as strictly a donor."
A sigh, then he lowered his head to look between them. "I'm all she has left. Please don't make me do that to her."
For that matter, don't do that to him. The part of him that he kept silent and locked behind a door that would've gladly stepped in front of that cannon without needing to be prodded by destiny taking a hand didn't know what he'd do if this blew up the first real thing that'd make him happy since losing his sister before it even happened.
He wasn't acknowledging that part of him, that was something that could just stay gagged and locked behind a door, at least for a little while yet. But that didn't change the need to protect Zelda's happiness.