Was it a repressed view similar to some European eras or a more relaxed opinion?
Were acts against the norm considered impolite or improper?
Which time period? Which region of the Americas? Which culture? In 1491 there were tens of millions of Native Americans spread from the Arctic to Tierra del Fuego and they all had their own views on sex.
Ok, I'm going to hijack and make the question more specific, in two parts:
I am a social elite in the Iroquois Confederation in the 15th century. What would I teach my kids about sex? What kinds of behaviors would I approve/disapprove of in regards to sex?
Same questions, except I am a 15th century Mayan farmer.
Assume in both cases that the Europeans haven't shown up yet.