why would you want to "save him from embarrassing himself further"???? didn't he do actual physical harm to you at one point??? (if i have the wrong person please excuse my error). why do you care if he makes fart noises at work? why would you even dream of telling him what YOU think he is doing wrong????
you put a lot of energy into his issues...you have to figure out why you feel the need to do this....give him enough rope and he'll hang himself....but don't get involved with his problems.
you are going to have separate lives...you need to live your own. you are joined by the kids, and their welfare. set a good example.