I think that doing as I would want to have done to me is the best bet for me. I would not want to be told flat off to just fuck off because someones wife or whomever else decides I am not what "they" want for their partner... that is bullshit to me. But, I would be very willing to negotiate something that works better for a partner that is struggling or even decide to let the relationship go because I can see they have far too much to work on before being truly ready for what poly brings to ones life.
There is no way in hell I would accept a partner of mines veto. I have come too far
I think veto and primary/secondary language and descriptions are for newbies. Those who are stuck in the realm of relationships where one owns another and isn't able to let go of that just yet. It's based on fear and that, I think, needs to be broached before stepping into being an individual in ones relationship... I get that. I don't operate like that, but I get it... we are fed it in every bit of pop culture there is... it's hard not to get it. I just don't do that, is all.