A variety of differing personal morals does not invalidate morals altogether. A foundational moral code can be derived rationally from the fact of self-ownership.
In short, what that gives you is the "Golden Rule", to do unto others after the fashion you would have them do unto you. The logical connection is that if I want my self-ownership respected, I have to respect everyone else's.
So while a person may hold a personal moral standard that public nudity is wrong, they must respect my belief that it is a matter of freedom of expression; if they come to a beach where I've already ditched my clothes and am building a giant sandcastle, they must either tolerate it or move on -- and similarly, if I show up at a beach where people are all clothed, it's encumbent on me to ask all those within a reasonable distance if it's okay if I enjoy nature au naturale.
Where personal morals end, however, is at basic rights. No one can tell others who they can associate with; that's a violation of self-ownership. So you can marry whom you please, and anyone telling you different, whether neighbor or legislator, is behaving immorally -- which means that every last person who voted for Prop. 8 in California, and those who sent money to support it, was in that instance immoral.
Concerning the topic of the thread, any who have declared that it is immoral for these two guys to do as they please is declaring a personal value -- and if they assert that people should be banned from doing such things, they are being immoral.