Originally Posted by AutumnalTone
Then don't enter into any agreement that involves vetos. It really is that simple. Nobody can abuse a power that you've not agree to give them.
Yup. Agreed. I honestly think we have vetoes in place in our relationship because of inexperience - it was my partner and his OSO's first foray into a real Poly relationship too, they read a LOT, and they incorporated bits and pieces from what they read. I can't personally see my partner unilaterally vetoing someone or something, period, without a lot of discussion behind it, so even though it's in place, it doesn't worry me. And even in the worst-case, I think I personally would just put all my concerns out on the table and let him make up his own mind (and deal with my end accordingly, either by having nothing to do with her, or something else). In our relationship, a veto is overkill and probably wouldn't be used.
But this is YOUR relationship - start off with what works for you. Eliminate what you know wouldn't. Revisit your framework as it changes. And live your life.