As a survivor of an intense three-year conflict with a narcissist, I have a word for everyone in a similar position: clarity. It looks like you`re moving away from your mother and children. Heal him and realize that the 19yo is not a child and that he is responsible for his own decisions and that 16yo is approaching quickly. You can`t save people from themselves. Focus on making your current relationship with your husband wonderful and don`t get distracted by the children from your problems. I agree, that`s the problem I had with my ex/Narcis. He was a police officer, so he «knew all the laws» and used his lawyer to force me and my son to contact him. I couldn`t walk away from him. Even when I visited my parents with my son, ex had to be in contact with his son. I was never able to get away from the stress he gave me.
I`ve never been happier when my son finished high school and decided to go into the military and be totally independent. I haven`t had to talk to my ex since my son closed the camp!!! People with narcissistic characteristics usually do not have strong emotional bonds with their children. Due to this fact and the fact that they do not put their children`s needs before their own, children may feel emotionally neglected by this parent. Be sure to compensate for this by assuring your children that they are good people and that they are loved. Your personal desires and requests won`t mean much to the narcissistic parent, even if they`ve accepted the ones you`ve listed. Narcissists love to use the justice system like a sword. But apart from that, they are also manipulative pathological liars who are sensitive to impulsivity and anger. Very thorough documentation will work to their detriment. Many co-parenting apps have private «notes» sections, or the notes area of a smartphone also works (be careful though to cloud memory and be sure to change all passwords frequently).
Keep an overview of every detail, including, but not limited to, the period the narcissist greets the children and sends them, how often they ask for a schedule change, when they appear late, what they fed the children, and what the children did during their parental leave. The smallest and most mundane details often appear later as a pattern. These models then become a powerful lever that can be very useful if there is an enforcement measure or a modification of the custody case.