It is technically more legal to screw a walrus than to get gay married
My favorite argument against gay marriage has always been the one about how, if you let two consenting adults marry each other, then it is just a slippery slope towards everyone wanting to marry a pony or whatever.
However, they might be surprised to find out– as I did this weekend on a Wikipedia bender– that while gay marriage is legal right now in only nine states, in 13 states, bestiality is totes legal, in three states it’s illegal but unprosecutable and in 20 states it’s only a misdemeanor. So, while one cannot legally marry a sea otter, they could at the very least dress it up in a bridal gown and veil and have quite the blissful honeymoon.
Perhaps unsurprisingly, there is quite a bit of crossover between states that have no laws against bestiality but do have laws banning gay marriage (or recognizing gay marriages from other states). For instance, Alabama, Texas and Kentucky — plus Montana and North Carolina, in which the laws are there, but you can’t prosecute.
It should also be noted that in 19 states (plus Washington D.C.), it is perfectly legal to marry your first cousin … and that, in five other states (including Arizona), you can marry your cousin if you are both sterile and unable to have a child together. This is especially fascinating given that other dumb argument about how only people who are going to be able to procreate should be allowed to get married.
However, if neither schtupping an antelope or playing kissing cousins tickles your fancy, you could always go to New Hampshire and marry a 13-year-old.