Rayne870 said:
Great...now we can conquer polygamy in the third one and then all the lonely New Zealanders will come out of the woodwork and demand bestiality for the 4th installment.
...
Jokes

Just a small joke amongst Australians, but I'm sure that it has no
real basis in truth...
OT: It's a pretty damned large step from homosexuality in video games to polygamy. Many people, including myself, see polygamy as objectifying, well, generally women.[footnote]Think harems and mormons[/footnote] For a medium that's already under constant criticism, and is viewed by many as nothing more than a toy industry, it would be hard to justify the inclusion of this.
Furthermore, it reeks of sexual fantasy to many - the hero goes through the game and gets all the women at once. Anyway, I had this entire little speech written here, but deleted it because it was essentially pointless.
The key things are that polygamy is generally viewed in a negative light, is considered offensive by many, would probably interfere more in a story than it would assist, seems a lot like pandering, there's no niche market for it, and it has no mass appeal - actually, just screw it.
Rest assured that it won't appear in any triple A video games for a
long time, and even the Indie devs would probably reluctant to approach it.
Sorry that post was so messy. I'm having a very hard time gathering my thoughts, because I've never even considered this particular issue before, and I've just taken the status quo for granted.