Veto Power: the Nuclear Option
Alt-columnist Mistress Matisse tells poly newbies something they need to know:
It's something you hear a lot when a previously monogamous couple decides to become polyamorous and start seeing other people. They say, "Of course we have veto power over each other's other partners. If something doesn't feel okay to me, then I tell my partner they have to end the other relationship."
I understand why people say this. My lovers and I said the same thing when I began practicing poly. I said it so my partner wouldn't feel insecure; my partners said it as a way of reassuring themselves that they had some control over the situation. Those aren't bad things to want. It's just that the veto clause is rather like the nuclear weapon of poly: Using it might neutralize one set of threats, but it's going to create other problems that won't have a quick fix....
Read the whole article (Sept. 13, 2007).
It's worth noting that some poly couples do use veto power successfully, especially if they're toward the friends-with-benefits end of the poly spectrum, where emotional attachments are less deep (but these things do sneak up on you).
Better than a veto agreement, IMO and filling some of the same needs is a Right of Consultation agreement. You get to meet your partner's prospective new love interest before things get too serious, perhaps over a nice dinner at your home. This is a good time to have the safer-sex discussion. Watch how the person reacts to this rather novel situation. This is likely to give you a good idea of their true feelings about polyamory, and their feelings about your partner's relationship to you.
It's also in-bounds to do a discreet background check for such things as restraining orders, an unmentioned husband or wife, or horrors splashed across LiveJournal or MySpace.
You can then calmly give your partner your best advice and counsel, and perhaps establish boundaries such as the person not getting into the house when you're not there. Do all of this just as early as possible. But veto? That's Latin for "I forbid," and it won't go over well.