Since no one knows the characters, I'll be general here. Say you have a male character who has a phobia about touching/being touched by women. He's not gay, but it's psychological and related to a traumatic childhood event. Now say over the course of the series, he isn't quite as paralyzed by this issue (he's able to save a female character's life by grabbing her, and he's able to carry another injured female somewhere for help), but it's still there and he's still not comfortable with the whole physical contact thing. But you want to pair him up with a female character because you think it'd be great, and you want to write fic, maybe more than one.
Here's the question, making a long story longer. How many times do you address his little problem in fic before you can just assume he does get over it at some point? Not all at once, but little by little. If you want to write something where they've been together a while, you might not address it at all, but then you'd have people saying you're ignoring an important part of his canon characterization. (And we all know what a heinous sin that is.)
Probably no one will read what I write, because I'm still in the beginning stages of writing for this series and won't have anything good enough to post in the first place, but when I do get to that stage, I want to be sure I'm not totally ignoring canon, but at the same time, I don't want to have to address the "no touching" thing every. single. time.