We no longer have a veto, though Wendigo and I have both volunteered to cool things down between us when Wolf or Pretty Lady were struggling. That being said, I have used veto once and only once and it was because a the time Wolf was incapable of making the decision to do what was necessary to keep himself, us, and our son safe (he was not working and was the primary care giver at the time). The woman he was seeing at the time convinced him to stop taking his bi-polar medication and he was [this] close to having a psychotic break..... I couldn't watch him put our son though another one, so I told her that it was over between them, kicked her out of our house, then told him that he could go stay with his mother until he was back on his meds and stable. It hurt to hear him tell me that he believed her, that he wasn't really bi-polar and that all of his problems started when I'd tricked him into marrying me by making him think I was pregnant (mind you I didn't get pregnant until we'd been married almost 3 months, but he wasn't thinking clearly). It took 3 weeks of isolation at his mom's for him to snap out of it enough to go back on his meds and 2 more weeks before I'd let him come back home.
Do I regret using the Veto? NO. Do I regret how I treated her at the time? Yes.