The equal rights of heterosexuals to have their marriages held up to question

Pandagon has a serious problem with Howard Kurtz's desire that every gay marriage should be about how sick and wrong it is. After all, if gays must have legal equality, can't we compensate somehow by trashing their relationships in the press?
Honestly, conservatives belief that cats can be squashed back into bags even though they'll be clawing and biting and tearing the crap out of everything around them until the stuffer gives up amazes me. It used to be that marriage was between men and women because it wasn't overly questioned. But now that it's questioned and conservatives want to enshrine what was never technically enshrined into law before, that marriage is by definition between a man and a woman, they have unleashed a potential legal nightmare.
For instance, say they get their way and somehow marriage gets defined as exclusive to one man and one woman. How do you enforce it? In most legal contracts, if there is a stipulation on entering it, such as age or credit or whatever, you have to prove it somehow. It used to be that people were just taken on their word for their sex, and marriages are actually made and have been made for a long time between members of the same biological sex who lived as different sexes. I have a funny feeling that conservatives who meddle in other people's bedroom practices are likely simply to accept that you are the sex you claim to be.
So what is it? How will "man" and "woman" be defined? Will there be a genital examination? If so, does that mean that transexuals and inter-sexed people will be barred from marriage altogether? What about transexuals who have such good surgery it's hard to tell? Who gets to judge? If the judge is someone so backwards that they believe in creationism manages to judge someone as inter-sexed who is not simply because her genitals might be slightly different than most women's, does the victim get to sue?
Or will we base it on birth certificate status, what the doctor declared you to be upon birth? This will immediately be a problem as well. For one thing, gay marriages will exist between natural born members of one sex and their spouses who were once opposite-sexed but have changed over. And again, alot of inter-sexed people are genetically male but deemed female at birth, but decide to go with their male identity as adults. Why should they be defined as "lesbians" and ineligible if they have male parts and want to marry women?
So I guess it will have to be a DNA test. But there are plenty of women who are genetically male, but there's way they'd know unless they took a DNA test. Do you want to be the person who tells a blushing bride that she's a man and a pervert in God's eyes for wanting what she thought was a lawful wedding? Do you want ostensibly straight men and women to "prove" their sex before marriage? What next? "Proving" fertility?
Like the one-drop rule that argued that to be black all you had to have was one black ancestor, the ridiculous nature of the legal distinctions has the power to cast a shadow of judgement over the unfairness of the entire system. Who's to say what makes a man and what makes a woman? If we decide who is to say, what gives them that authority? And aren't ordinary men and women going to revolt when they have to "prove" their biological sex just to obtain a marriage license?