Why did Prince Harry twist this man's nipple?

When lovable royal nerd Prince Harry sees a nipple, he tweaks it. At least that's what happened at the Invictus Games a few weeks ago, when Prince Harry met a British man at a volleyball match, looked at a new tattoo on the guy's bare chest, and twisted his peck — just like the boys in your third-grade gym class. How old is Harry? Thirty-one years young.