Been there. Short answer, we don't want to live with that shit on our head. We don't want the guilt or the responsibility, in case he's serious. He isn't. My ex did the same fucking thing, but I was wise to it by the time he did because he did the same thing to his previous ex wife. I called the cops to perform a welfare check on him. I didn't give a shit about him, just didn't want it on my head. He was fine, sitting in his truck at a coffee shop. He tried it a couple more times, same result, until he was finally held for a Psyc evaluation...funny, he was just peachy.