Excuse me, but between today and a certain man named "Moses" the standard of adultery has been the same. And even between now & the beginning of peoplehood -- what Jesus referenced as "at the beginning" -- the standard was one wife:
"Haven't you read," he replied, "that at the beginning the Creator 'made them male and female,' and said, 'For this reason a man will leave his father and mother and be united to his wife, and the two will become one flesh'? So they are no longer two, but one. (Matthew 19:4-6)
And if you're not talking about either adultery or polygamy, you're not going to become the pedophile's apologist, are you, by trying to tell us that sexual relationships with young teens (on top of already existing marital relationships) was A-OK as long as you hit some "ripe" spot on a calendar?
Moses had TWO wives. See Numbers 12:1