The shirt originally said, "Some people are gay. Original pin: Get over it." They were made as part of a demonstration for gay rights in the UK. Sir Ian McKellen has been an outspoken advocate for gay rights.
"I'm a supporter of gay rights. And not a closet supporter either. From the time I was a kid, I have never been able to understand attacks upon the gay community. There are so many qualities that make up a human being... by the time I get through with all the things that I really admire about people, what they do with their private parts is probably so low on the list that it is irrelevant." Paul Newman