same sex marriage has all happened in recent times
Wrong again. From the wiki:
Various types of same-sex marriages have existed,[37] ranging from informal, unsanctioned relationships to highly ritualized unions.[38]
In the southern Chinese province of Fujian, through the Ming dynasty period, females would bind themselves in contracts to younger females in elaborate ceremonies.[citation needed] Males also entered similar arrangements. This type of arrangement was also similar in ancient European history.[39]
An example of egalitarian male domestic partnership from the early Zhou Dynasty period of China is recorded in the story of Pan Zhang & Wang Zhongxian. While the relationship was clearly approved by the wider community, and was compared to heterosexual marriage, it did not involve a religious ceremony binding the couple.[40]
The first historical mention of the performance of same-sex marriages occurred during the early Roman Empire.[41] For instance, Emperor Nero is said to have married one of his male slaves. Emperor Elagabalus married a Carian slave named Hierocles.[42] While there is a consensus among modern historians that same-sex relationships existed in ancient Rome, the exact frequency and nature of same-sex unions during that period has been obscured.[43] In 342 AD Christian emperors Constantius II and Constans issued a law in the Theodosian Code (C. Th. 9.7.3) prohibiting same-sex marriage in Rome and ordering execution for those so married.[44]