Childs Out bursts and violent behavor?

(1st-excuse the spelling since alot like to make a point of it) Im in a relationship with a child involved thats not mine.this child 7 years old has Disabilitys.ADHD and ODD.(Defiance Disorder) and insomina so he will be wide awake till 3-4 Am. bottom line when he get frsturated he has violent out bursts.throwing toys.screaming.Ect also when he is told to do somthing he has to be told (ive counted 5 times) before he either dose what he's told or has out bursts.the mother.(my GF) likes to scream at him and call him names but when I say somthing im told to either deal with it or get out.the father is still around so the child spends every other week with him.lets just say I know were he gets his problems from.mother & father.ive been with this woman over 1 year now but 1 year ago these problem were not as bad.so the older he gets the worse they get.my problem is I basicly have no right to say anything when she is aloud to have her out bursts at her child.as im told since im not his dad I cant say anything.Im guessing im the wrong one for staying with this woman knowing of these problem when im the only BF that has stayed and delt with it.I do love her but I been backed into a corner.What dose love do?