However, since it's likely to come up again, have you considered conceding her point that you'll have to meet OM some day? I don't mean agreeing to meet him right now, I just mean not arguing that you never will. She might be imagining a world in which they are together long term, which means there will be graduations, weddings, etc., where both you and OM will be attending. She might see you arguing about meeting him as pursuit in a way--denying that her relationship with OM is real.
What if you just responded, "Maybe I will, but it doesn't have to be today, and it doesn't have to be at the house"?
That might let you hold fast to your boundary without engaging in the argument.
And I agree with those who say to reassure your sons that nothing bad will happen if you and OM do meet.
Me: 44 H: 44 Kids: 20, 16, 16, and 10 Together/Married: 22 years H announced he was emotionally detached and considering D: 4/4/16 H announced he is going to try to stay and reconnect: 5/1/16
