There is a reason I don’t like cheating AUs for certain characters. However, Veneziano isn’t completely loyal either, he did betray the Central Powers, along with his brother, in WWI for land (though not shown yet). But in romantic ventures, he and his brother are good lovers (flirt maybe but cheat?). I suspect old survey result is behind some thinking. I don’t think either brother would cheat, goes against char. I suspect Seborga or Genoa would though, but we don’t got a lot of info on them.

I disagree. Politically, he may be disloyal, but personally he’s loyal to the other nations as friends. That’s an important distinction that’s always been cemented in the series. 

Ex: Even though they were enemies during WW2, he still greets France as a friend when they’re stranded. 

The decisions of his bosses are not reflective of his character as a person. 

Side note: Italy only met Germany in WW1 after he had switched sides by the way + being a player doesn’t always mean cheating on a spouse. It can mean having several non-committal flings, one-night stands etc. while still remaining single.