divorce

OK so long story short... I'm married we have all together 7 kids I have custody of 4... 3 live with their bio mom and guardian.. i currently reside in his family garage.. i pay rent plus our own food and help with the house... I was working but due to health issues and then two of my kids needing to be hospitalized we felt me staying at home would be best... I've filed for divorce and cs... anyways recently his son has been physical towards my 4 year old ... both boys have been caught lying and yet nothing is ever done only my girls get disciplined...and god forbid I mention anything to their mother or anyone in their family and I get told its my kids fault they are crazy and act bad... its to the point I dont want his boys around my girls... I suggested counseling and got told off ... but let me ask you what type of child smacks a 4 year old upside the head for singing... or placing said child in a choke hold while I drive?