Mother in law and her teenage son have lived with me since August. The level of disrespect and "logic" that has come out of his mouth would make any man cringe. I would take him out back and beat the breaks off of him but my wife says it wouldn't do him any good. I told her I would be better though.
And yeah, I get tag teamed at times with my wife and mother in law. They find something they want to do and then come at me together saying we should do this, like buy her teenage son some $150 shoes or build some ****ed up art thingy they found on Pintrest or move furniture in a spot that makes absolutely no ****ing sense. Sad part is when most of the time when I say no, it's still done anyway when I get home, and they still want me to actively support that decision...
There's a simple fix for all that. Look directly into the face of the MIL and quietly say "Get the **** out!" Then look at the wife and add "And ANYONE who has a problem with that can go with her".