One of my pet peeves is when suddenly everyone becomes on expert on some foreign country's customs (usually Arab or Asian countries) and conclude there is some sort of body language which is Unbelievable Offensive and Thing The Which Must Not Be Done. The latest version of his was that giving a thumb's up sign, which Trump does, was Very Offensive in Saudi Arabia. I have no idea if this even true, but even if it is the kind of thing locals don't do it isn't as if they're going to be mortally wounded if Trump sticks his thumb up. If someone came in my house and promptly flipped me the bird, an offensive bit of body language in our culture, I'd find it weird but I wouldn't actually be offended. How dare you, sir! I have been insulted! I mean, whatever.
Yes of course there are different manners and customs but people generally recognize them for what they are, and if somebody foreign doesn't know the proper silverware etiquette or whatever no one is really going to get too upset.
