Your Wikipedia "facts" (assume you typed in same sex marriage) basically refute your own argument. After reading that section of the page, almost all the examples point to the fact that homosexual relationships existed (big surprise) but were not traditional unions within their various cultures. The Mesopotamia statement doesn't even include a useful reference (ibid, wtf?). Funny how you leave the most important part of that section out too:
It should be noted, however, that conubium existed only between a civis Romanus and a civis Romana (that is, between a male Roman citizen and a female Roman citizen), so that a marriage between two Roman males (or with a slave) would have no legal standing in Roman law (apart, presumably, from the arbitrary will of the emperor in the two aforementioned cases).[85] Furthermore, according to Susan Treggiari, "matrimonium is an institution involving a mother, mater. The idea implicit in the word is that a man takes a woman in marriage, in matrimonium ducere, so that he may have children by her."[86] Still, the lack of legal validity notwithstanding, there is a consensus among modern historians that same-sex relationships existed in ancient Rome, but the exact frequency and nature of "same-sex unions" during that period is obscure.[87]
Referencing the interpretation of obscure ancient texts sure is convenient when trying to support an agenda, but when it comes to the most followed and enduring religions of our time, ancient texts and scrolls quickly become scoffed and discredited.