Life as we know it

My son's father has decided he is a parent. Not that he has lived with my son for the past 15 months, he quit when his wife and my son got into an arguement. He did not stand up, he made no plan, he threw my 14 year old son with Aspergers to the curb, no coat, no ride, just abandoned like an old chair.
My daughter snuck him a bus pass, and he found his way to my house. I took him in and for the last 15 months we have supported him through therapy, one huge fit of anger, a trip to the hospital, the police, and his having to learn how to adjust, and now my ex has decided he is a parent.
My ex won't call the adults and talk with them, or send an email without threatening them. He actually yelled at my son, and then my poor son, who was trying to talk to his father actually spent 20 minutes begging his dad to calm down, and then 15 yelling at me because I wasn't willing to be yelled at.
How do you become a parent without any knowledge of your own child? How do you lie to the lawyer, and god only knows who else, about how great you are at parenting when your 13 year old daughter is up at midnight?

My son needs stability and I want the best for him. I want the best for my children, and how can I supply these and still allow him to see the children? I want to keep my sanity.

In the Beginning - How did I get here???

My son Alex is 15 years old and he has aspergers, my son Josh has Attention Deficit Hyperactive Disorder or whatever the newest name is. Funny how life works, One won't sit still and one won't move.
My pregnancies were normal, no drinking, quit smoking, ate well, and yet, I have these 2. I have 2 other children. They are girls, and one is a diva and one is off to college, and they are just pretty girls who live their lives with normal teenage angst, drama and life.

The boys are a wonder of ideas, thoughts, movements, and here we sit. This is my I need a break from the insanity of them. If you can't talk to someone, prepare to die alone..