It's different when you play as Tav though. Not all the companions are available for a poly/open relationship. So you can play an origin character as poly, but you can't have a poly romance with them as Tav? Makes no sense.

Larian wanted to give us player freedom by making the companions playersexual, yet they take away our freedom by limiting poly romance to a few characters. It's especially limiting for straight men and lesbians, who aren't given any options.

I really hope this gets fixed in the near future, as I can't see why romancing a couple origin companions at once could be a problem. We certainly can't use the excuse that a companions characterization doesn't fit because Larian cleary doesn't care about that. So they mine as well go all in on player choice and allow ALL companions to be open for poly or mono.