In the odd chance that you live in a bubble (which arguably, some could stipulate the President does), you would not have known that Dell Martin and Phyllis Lyon got hitched again yesterday. Have a look at this happy couple and ask yourself, how are straight people harmed by these two getting married?
I'm still awaiting a plausible rationale that helps me understand how two octogenarians getting married hurt the institution of marriage. What is it about heterosexual marriage that needs protection? Because the "bible" tells us so, doesn't apply unless you adhere to a strict interpretation of the document. Where's the harm?
Really, I might argue the contrarian - in fact, the very act of Dell Martin and Phyllis Lyon getting married only strengthens the institution - as they have been faithful to one another for a lot longer than many heterosexual marriages have lasted.
If one was really concerned about what harms marriage, perhaps we should outlaw divorce first. Or alternatively, ban celebrity marriages as they end in divorce at a higher rate of those in the ordinary community. Or, even more to the point, let's ban marriages between smokers or fat people as the statistics actually indicate that if children are born to obese or smoking parents, there is a higher probability of those children following suit (which is inherently bad for their health).
So, until some one can prove that there is a harm to their marriage because these two women got married, I'll stand and celebrate with them. Why not join in the fun! There are going to be a lot of very happy, salubrious parties to jump into. Where's the harm in that?