Hi there! My life partner and I are non-hierarchical polys with no veto. (Currently neither of us are seeing anyone else but we have in the past.) You can talk to me about this and feel free to PM me because I'm not very good at keeping up with threads.
Although we don't have any veto over who we date, we are ok with sharing our opinions and preferences. For example, not too long ago there was this woman my partner was interested in. She would give me dirty looks now and then (at least it seemed she was) and I told him that -- not to say he couldn't date her, but to let him know it would be awkward. He decided not to pursue dating her but that was his own decision.
In other areas of our relationship it's the same -- not rules but stating our preferences and considering each other's feelings. The only rule is practicing safer sex!