I don't know what's going on with your ex-husband; however, if your fear him or feel like you and your children are in danger you should immediately seek help from your local domestic shelter or police department. Domestic incidents happen all to quickly it will snowball out of control. Never underestimate what a person say they will do because they do worst most of the time. If he's threating you please take him at his words, otherwise, take him serious, I can't stress it enough, if not you for your children sakes.