What is a 'veto' in polyamory, and is it a good idea?

A veto in polyamory is structurally a power: one partner — typically a primary — can require their partner to end another relationship. In strong forms, the veto is unilateral and doesn't require justification: 'I am calling the veto on that relationship' is sufficient. In softer forms, it triggers a deeper conversation, time-limited distance, or specific changes, with the end-decision still requiring discussion rather than fiat.

Strong vetoes are widely critiqued in contemporary polyamory writing — by community elders, by clinicians, and by people who themselves had veto agreements early in their polyamory and decided to abandon them. The core objection is that a strong veto treats the outside partner as a person who has no real standing: their relationship can be ended by someone they aren't even in conversation with. A relationship that exists on those terms is structurally precarious in a way that tends to make it impossible to deepen, which then guarantees it stays shallow.

Defenders of vetoes (mostly in the early stages of opening a previously-monogamous relationship) argue that a mutual veto can provide enough safety net for a nervous primary partner to consent to the structure at all. This is sometimes true, and is one of the cases where a soft veto — used carefully, retired explicitly once the structure has matured — can be defensible.

What works better than veto, in most modern writing: explicit attention to one's own boundaries (what behaviours you yourself will or won't engage in if certain situations arise, which is in your control), structured check-ins where concerns can be raised early, and the willingness to have hard conversations about specific relationships when something genuinely isn't working. These produce outcomes that are sometimes the same as a veto's outcome — a relationship ending — but they arrive there through process the outside partner can participate in.

Read More Than Two for the canonical critique of veto power and the book Polysecure for an attachment-theory frame on what stable structures actually require.