My son (22) has always had an aggressive side and tbh I generally feel I have to walk on eggshells with him as he can be unpredictable. Historically he can get angry at inconsequential things and now he is an adult (he's 22 and still living at home) he has turned into the alpha male of the family (I have 2 daughters also living at home).
Last night he and his girlfriend were having a night in, and we had a nice evening watching tv. When he went up to bed, he discovered that one of our dogs had shat on his bed (I'd like to add that this is an unusual thing to have happened and the dogs are house trained). He absolutely exploded, swearing, threatening to 'kick the fucking dog' and generally being aggressive. His gf and I laughed it off, told him not to leave his bedroom door open and between us we changed the bedding. DS continued to shout and rant about chucking the dog down the stairs at which point I told him to stop over-reacting. He began to shout at me to get out of his fucking bedroom. I asked him to not swear and shout at me please, to which he replied fuck off fuck off fuck off repeatedly. I began to back off but decided to alpha him and so stepped into his personal space and said clearly 'please do not speak to your mother like that' he said 'well I just did so fuck off' and pushed me out of his room.
At this point (sorry this is quite long) my younger daughter (19) came into his room and shouted 'do not push her or shout at her like that, she's your mother'. She went to push him back and he grabbed her in a headlock and threw her on the bed holding her in a headlock. I was shouting at him to get off her, but DD said bravely, 'its ok mum, i'm not scared of him'. DD got up and pushed his chest, and he responded by putting his hands around her neck and pushing her out of the bedroom and then shoved her against the wall with his hands round her neck. I was shouting at him to get off her - her face was going red. He let go and shoved her against the wall again and left the house in his car.
Later I heard his GF speaking to him on the phone and he returned and went to bed. They have gone out for the day now with ExH who I have briefly given details of last night to. He said 'I'll deal with it'.
I just don't know what to do. I am so sorry this post is so long and hope that some people may have some advice. Should just add that ExH from whom I am amicably divorced is still very much present in our lives (we divorced 10 years ago).
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abusive son - quite long but desperately need advice
purplenights · 21/02/2016 08:59
If you don't deal with him then he is rewarded for violence, he learns that it works and he'll do it again
Live by the sword
die by the sword 
You are also completely deluded about the impact of what he did, op 
. They're terrified of him, and you'll let him escape the consequences of physically attaching them "to try to stop the widening gap between the siblings"...
What relationship do you think there'll be left to salvage if they watch you do that??
At that age he'd be out the f*cking door! I am fuming reading that. 
I don't want to repeat what others have already said but get him gone. He wouldn't come back in my home again until I had seen concert evidence of awareness of how wrong he was.
I have a friend with a son like this, totally out of control. It has been allowed to continue and now he is nearing 40 and has a wife and several dds. He is abusive (verbally) to all of them, including, actually especially to his mother. He hates women, and is surrounded by them. He's a very unhappy man and all the females in his life are frightened of him.
That last comment of his about jumping off a cliff is what is so worrying. Because by that reaction, he clearly thinks how he is behaving is acceptable. He's not in the least bit sorry.
Your ExH says you involving the police is what will ruin everyone's lives. So, he doesn't see that DS's behaviour is ruining everyones lives. That's what needs to be stopped. He is not going to be any help in this situation, he thinks he has the right to tell you what to do, and he doesn't seem too bothered by the fact that his own daughter has been assaulted.
As someone said earlier, it is not up to your ExH to decide how you deal with things in your own home. He certainly isn't going to keep you safe. Your son is 22. So he can go off and find his own home. Because behaviour like that is no longer acceptable in yours. Sorry OP, but he has to go.
He´s bullying you and your daughters like your husband bullied you. God only knows wot his girlfriend sees in him!
Next time he turns on his sis it could be a lot worse. She could pass out or incur brain damage from lack of oxygen. And the disgusting way he sees fit to speak to you....! He has zero respect for any of you.
It´s assault just the same as it would be if it happened to strangers. This isn´t just siblings squabbling anymore. He thinks he can treat you women with contempt and disdain. He´s carrying on like he doesn´t even like you!
It´d be still unacceptable if he apologised but it´s very worrying that he doesn´t even seem to see anything wrong with his behaviour, so no reason to say sorry! 
This is utterly shocking. It will only escalate.
I would tell your ex to butt out, he wasn´t there to witness this assault and doesn´t live with his shit son! Your daughter should´ve gone to the police there and then.
This is domestic violence, he´s broken the law and is a threat to the welfare of you all. The safety of you all is compromised as long as he resides with you.
The welfare of your daughters should be your priority here. Please deal with him like the criminal that he is. There is something faulty within him that you cannot fix. Please don´t make the mistake of being a victim and suffering further abuse cos you think you can change him. Your daughters deserve a strong, decisive mother who will protect them and act in their best interests. Letting him stay and get away with murder is not acting in their best interests. You have a duty of care and it is not to him.
He´s dangerous because he thinks itś acceptable to demean and physically attack women. Contact police and get rid of him. He is not a small child/teenager anymore, where bad behaviour can be excused. He must be held accountable like the adult he is.
He chose to attack your daughter and he chose to say those nasty things to you. So please be strong now, for the sake of your young daughters, do the right thing.
I could understand your reticence if he was much younger, but he is 22. He's got a car and a father who could put him up until he sorts out somewhere else to stay. He won't be out on the streets. Wishing you strength to make the decision that you and your daughter deserve better than to have to live like this 
.
God he sounds awful! Totally unacceptable behaviour, very dangerous also very cold & hateful - the driving off the cliff thing
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