I don't mean to sound stand-offish, but what has caused everyone to think that there's only one Latias and one Latios? I mean, there were at least four Latios and two Latias shown in the movie. It's genuinely confusing to me.
Was it the games, where you could only catch one of each? But then the pokedex entries explain that they form small groups, so...?
Anyway, yeah, I would be a bit uncomfortable writing twincest. As I just showed, though, I could do a story about two Latis that aren't related. Would that be okay, or did you pick the Latis specifically because you wanted twincest to be present?
I'll try to stick that in the Lati one-shot somewhere, when and if I write it. I drive a Toyota Station Wagon, so I know how wonderful that type of car is.
"Latios reclined on the hood of his Buick Roadmaster in human form, gazing at the crimson sunrise with half-lidded eyes that matched nature's colorful display."