I'm surprised it's not an American this time [Okay yes this is 100% a joke, since I'm also American]
However, there's a line between being proud, and boasting. I'm proud to be Cuban American, my father being native to Cuba. In fact, I like to see people who take pride in telling others where they're from. It's rather interesting to learn, and to see people who care that much to say it to complete strangers.
But the line draws when they flaunt it, yes. When they say, or imply that their country is better than others, or has something better than others, etc. That's not right. Since, they are opinions, and as we know those tend to get out of hand in game.