Dating native american women
The girl's mother's sister would speak to the girl's matrilineage about the idea, often without telling the girl.
If the matrilineage liked the idea, they would send word back to the boy's matrilineage.
While sex in the fields certainly occurred from time to time, it wasn't a proper place for such activities as it made the future use of the fields and the consumption of the crops "problematic," to use Purdue's word.
Purdue cites the "pollutiing" influence of semen (and bodily fluids in general) as the reason for this.
Whether their Southern Iroquoian cousins shared this tradition once upon a time, I can't say.
This is a very foreign subject to most modern "Western" people today.
While Perdue doesn't mention it in her book, I wonder if these short-lived marriages are actually a distinct class of "marriages" related to those mentioned in Barbara Mann's (which is focused on the Haudenosaunee and Wendat rather than the Cherokee).
I'll discuss that in another post, but here, I'll just mention that among the Northern Iroquoians there was a tradition of almost-marriages before actual-marriages, a distinction frequently lost on Euro-Americans.
Divorce existed and could be initiated by either party.
Cheating was frowned on and punishable among the Creeks (neighbors of the Cherokee), while the Cherokee allowed both women and men relative sexual freedom of lovers, although women could not marry multiple men or keep concubines. Although the gender division of labor is different than that of contemporary European societies, I can't find any clear evidence for a third gender among the Cherokee specifically.