English common law contains the fundamental principles that the Constitution is based upon, and were the laws in the colonies prior to the establishment of the Constitution.
Part of the English common law is the definition of marriage.
Again, read Reynolds. It’s all there and the Supreme Court lays is all out for you.
Which chapter of the US Constitution covers that and please avoid references outside of the wording of the constitution or specific interpretations if the wording by someone who had the authority to do so.
BTW British common law said if someone killed your mule or horse, you could compensate for two pigs. Did I miss that in the constitution?