Marriage is a contract.
Government has some role in the enforcement of contracts.
I don’t see a problem with this, except that the government has over-stepped it’s bounds, as usual.
Get the government out of the marriage business. They don’t belong there.
A bull can marry a sheep for all I care.
But, contracts should be enforced.
And society has a real interest in regulating, through government, maternity and paternity. Given that all human reproduction occurs through heterosexual activity of one kind or another, homosexuality has abolutely no relevance when it comes to the civil institution of marriage.