Considering that non-jews must abide by the 7 laws of Noach, including sexual immorality, at what point is a goy considered married ?
At what point is he considered divorced ?
Can a goy have many wives ?
There is some controversy about this. However the two non-Jews would surely be considered married when they have marital relations with the intention of them living together, (and not just for promiscuity). Regarding when they are divorced, there is also controversy about this, but according to Rambam a gentile woman is considered divorced for her husband when the two separate from each other. Regarding marrying more than one wife, if it is legal in the country that they live, I don’t see an issue in relation to the 7 laws of Noach. The prohibition is to marry someone else’s wife, but not as far as the amount of wives they may marry.
Rambam Hilchos MiIachim 9-5, 8, Toldos Noach 7-8,11.