My son has the same diagnosis. He had been having outbursts for a while but had never done more than threaten violence against family. No one took him seriously. Now he has crossed the line and become physically violent against his step-dad (this after close calls with two uncles.) He is now on medication (one of the conditions we have given him if he wants to continue living with us) and in therapy. I never thought I’d be afraid of my own son or that his outbursts would escalate to this point. He is always remorseful after an outburst but that does not undo the things he’s done. Please be careful and think things through. I understand you care about your partner but this is a lifetime problem and only medication and therapy can help (not cure) his issues. I hope he is willing to get help.