Emotional Terrorism

My eldest daughter and my son are on a path to drive my ex-wife Angela crazy and I don't know if I should try to help. I know I should but I told her all will come back to her 10 fold. My eldest is leaving dishes and cups in her room whom she shares with her sister and they are constantly fighting over my eldest turning off the lights at night so her sister can go to sleep. Angela is constantly fighting over the power bill that it's way to high and my daughter needs to get off the laptop and go to sleep at a normal hour. I don't see this fighting ending anytime soon. But here is the real dozy my son plays this PC game called World of Warcraft and he has begun to stay on it till all hours of the night and not going to school the next day because he's tired. I say to bad and go to school but I don't live there so she just lets him stay home because she doesn't want to fight with him. So now he playing the game. He can spend all night on the computer and not go to school the next day cause he knows his mom will not fight with him about it. But she calls me to complain about he's on the game all night and he's not going to school. I ask are you waking him up and moving him to go to school or taking the easy road and just not engaging him to go to school. She said I just don't want to fight with him about it, then he's won I said. I try to talk to him about his school but when he gets back to the house he gets upset and tells his she a bitch and a liar. He has been on a terror with his behavior towards his mom. I try to ask him why he does these things and he replies because she deserves everything she is getting. I told him is it because she divorced me and he said yes and that she destroyed our family.. I told him what happened between your mom and me has nothing to do with you guys and you need to respect your mom cause she's your mom regardless of what she's done. He replied when she starts giving respect then she'll get it and not until then. Well, I can't argue with that. I spoke to Angela about this and what my son said and she asked me if she deserved what she was getting. I didn't answer her but in my head I was yelling "YES". She said all she wants to do is get some sleep but he's all day, all night, laughing, cursing and typing on that dame game. I told her I would try to put the parental controls on the game so she can get some sleep for once and we age ed on what time the game would be ending. I put the parental controls on the game and when it shutoff in the middle of a raid he went crazy in the house and Angela called me at around 11pm(I was sleeping) because they have been fighting for an hour already, she asked me to remove the controls and I told her if I do this, this will be the last time I want to hear of this. She said turn them off and I did. He realizes that as long he's acting like this he'll get what he wants in that house. Angela called the other day asking if I would pay for a month of World of Warcraft for my son and I replied are you out of your fucking mind because if I do that I'm condoning his behavior towards you and I don't so I won't. I'm sorry I said but I told you I don't want to hear of it again. I tried to help but you won't keep up a united front regarding this issue. I'm done with it.