"Jesus would rather kill, not marry, gay people" - Franklin Graham

[Angrboda]

As noted in another thread, the fact that same-sex marriages had to be explicitly outlawed seems to strongly suggest that same-sex marriages were in fact a reality at the time.  The idea that they would make a law outlawing a practice that did not occur is absurd.  And thus, Steve's contention that same-sex marriage does not exist in history would seem to be an exaggeration, at best. 

Not at all. A law against it could also mean that some either tried it, proposed it, or heard of it and the powers that be employed the same reasoning I did to deny the change in definition. Without more information you are making a lot of unsupported inferences. For example, if the modern courts had upheld the traditional definition, you would never say that same sex marriages were part of the definition of marriage. You would be arguing in a circle.