Actors Patrick Stewart and Ian McKellen are best friends. Stewart often posts on Twitter photos of the two of them together, palling around in their signature derbies. Here's one that he just put up. It shows them in front of the Stonewall Inn in New York City.
The Stonewall Inn is an historically gay bar in Greenwich Village. Police raided it on June 28, 1969. Gays fought back in an event known as the Stonewall Riots. Many historians regard this resistance as the birth of the gay rights movement in the United States.
P.S. Be sure to check out this hilarious animated .gif showing Stewart and McKellen. It mashes up a scene from the latest X-Men movie with their photos together. In the movie, Stewart and McKellen play Professor X and Magneto, longtime enemies.