First SSM, then polygamous and incestuous “marriage” won’t be far behind. The same principles apply.
It’s not a matter of what next . . . or what this leads to. The thing itself is harmful, above all to children. Just google “Elton John’s children” for a prime example.
I want to marry my cat, Smoky. Plus he’s got disabilities and can never work at a full-time job like I do, so I will get to claim him as an exemption and a dependent. I want to demand vet insurance from my employer to cover his little healthcare needs.