Nathan knew he still deserved to have this ruin his marriage, but he didn't want it to come to that. He didn't see it as something that had toppled their marriage entirely. He had struck multiple blows into the foundation of it, for more reasons than just his infidelity, but all these months had been focused on repairing all of that, and rebuilding what had been broken entirely, like her trust in him.
There was no right way to answer this, and many ways that would all simply come out wrong.
He'd buried the events of that night so far in his mind, it would likely take a skilled mind to find it, if they knew what they were looking for. It had been a defense mechanism of guilt, and in ways it still was, but mostly now it was that he didn't want those memories to taint anything in his mind that was worth remembering. He could never explain that properly, he was certain, but it seemed he might well have to, even if he feared his attempt to show her that he had dismissed it would only hurt more if it was taken as a dismissal of the entire thing. It wasn't, only a boxing up of those moments he worried she spent far too much time thinking of – not just his infidelity and what she thought it meant, but the act itself.
There was no comparison to Heidi, there never would be. To him, she was in a league far above any other woman. That he had shaken her belief in that was something that hurt him even now, but this wasn't about the hurt he knew he didn't deserve to give weight to, it was about her hurt. He'd take her lashing out at him if it would help her at all.
"That's what my mistake looks like," he finally said. "And that's all she is to me, a mistake I made. I want what we've been working on all these months, our marriage. Not toppled, just in need of repair."