There's nothing "unironic" about it. You think the government should tell consenting adults that they can't bang each other? I don't. Just because you or I might find it repulsive doesn't mean the government has the right to imprison you for it. That's how homosexuality and mixed race relationships were outlawed to begin with.

Here's the thing: You're both right.

(Disclaimer: I am discussing incestuous relationships between two consenting adults. Relationships with children are and should be illegal already, regardless of family relationships. The same goes for non-consentual relationships. Those are just straight up rape and should be treated as such. At no point should anything I say be taken out of context or imply that I condone some 40 year old pedo diddling his 12 year old niece. That is, always will be, and always should be considered straight up rape with the perpetrator being jailed for life.)

One of the big talking points on the right when it comes to restricting gay marriage is the argument of "next, people are going to want to legalize incest". (Or pedophilia, or beastiality, or whatever. They make them all.). Any attempt at removing any time of restriction around incest is going to IMMEDIATELY be met with fierce resistance from both sides, with the republicans especially out there basically saying "See? I told you!". Any attempt at validating incest would almost certainly have a negative impact on marriage equality in general, and I really don't think there's all that much of a community out there of people willing to legalize incest, even if it is between two consenting adults who cannot bear biological children. Regardless of your opinion on the subject, the political will is just not there and any attempt to do so would be guaranteed to cause far more harm than good, particularly in the LGBT community no matter how much they would try to distance themselves from the idea.

But with that said, there is a point to be made about sexual relations between consenting adults who happen to also just be genetically related. Let's be realistic: Some 50 year old guy having sex with his 50 year old cousin down in Alabama isn't going to hurt anyone else. In reality, it's nobody else's business. They're never going to have children. And hell, if they don't say they're cousins, they could go the rest of their lives without anyone figuring it out anyway. A point could be made that these people deserve the same rights to be with their chosen partner as much as anyone else does.

The problem with it, though, is that even among otherwise consenting adults, you can't guarantee that there's a power dynamic influencing their decisions. It's one thing, for example, if Steve and Sarah fell in love then found out they were long-lost siblings. It would be another if Steve was her older brother and was basically the "dominant" sibling of the two for their entire lives, or even in a father-figure type of role. Then it becomes a matter of mutual consent vs. that dominant role he had played extending beyond normal sibling relationships. Same could be said for cousins or any other family relationships. There's way too much muddy water there that would be ripe for abuse.

Honestly, I could see an argument for relaxing some incest laws in limited circumstances. While I have no data to support this at all, I'd be willing to bet that accidental incest probably happens more often than we would think. Think about it......one deadbeat dad has 5 or 6 baby mamas around town. Do you think anyone is able to keep track of all of the first and second cousins those kids have? I'd be willing to bet that most of these kids have no idea how many cousins, if any, live in the area. And given the prevalence of absentee fathers in some parts of the country, it's not unrealistic to think that some of these kids may even be boning their half-siblings without ever realizing it. I'm not saying there are entire towns who should change their anthem to Sweet Home Alabama or anything, but I'd be willing to bet it happens more often than people think.