Great Moments in US-Irish Unity

I was out jogging earlier between Cadogan Square and Green Park, wearing the Boston Red Sox baseball cap that marks me unmistakably as an American. I passed a construction worker who smiled and said something to me in such a thick Irish brogue that I couldn’t understand him immediately, so I just smiled, nodded, and kept jogging.
A few seconds later, my brain finally translated his comment: “What, not a Yankees fan, are ye?”