I am in a social group which is organising an event at the Coronation. I am rather fervently anti-royalist. Some of them are very pro-royalist, which is their business. Is there a polite way to decline without fibbing or offending others? Can I just say briefly," Sorry, that's not my thing." They already know I am not travelling as I committed to the group before I realised they were doing a coronation event.