If this was a civil ceremony, then who the heck cares? Civil government - Caesar - can pretty much do as it pleases. It could recognize as legally meaningful the relationship between a human and a chimpanzee if it pleases.
The issue is - as it has always been - whether private religious communities - by that I mean churches, not civil towns or cities in which lots of people who believe live - are forced to recognize/respect relationships like this that are anathema to their personal beliefs within their own private affairs and organizations.
And quite honestly, such over the top, angry, responses from people who dislike them simply validates them; if you want to emphasize the meaninglessness of it, then ignore it or dismiss it quickly as being inconsequential. If you want to be dismissive and insulting at the same time, you can always say: "eh. The government can always let you marry a monkey if it wants to."