It's nice to see you Ranger Jack (:
Anyway, I was looking around and found a quote that really reminded me of Advanceshipping, which sort of pertains to what we've been talking about:
"They’d never been lovers, of course, not in the physical sense. But they’ve been lovers as most of us manage, loving through expressions and gestures and the palm set softly upon the bruise at the necessary moment. Lovers by inclination rather than by lust. Lovers, that is, by love." ~Gregory Maguire
I think this about sums it up. Sure, Ash and May have never been in a relationship (and all things being equal, may never be so long as the writers don't want to lose a portion of their fanbase) but the way that they interact, care for each other, respect each other, comfort, treat, and otherwise learn from each other is what matters. It's not so much a label as a "couple" that we're looking for; it's more about their actions.