What ground does my gm have?

I'm a manager at a theatre. We are a cooperation and my GM told the salary manager who make the schedule to not schedule me and another fellow manager together. We have only worked once together and after that he told them never to schedule us again. That day a few things went wrong but everything was handel and not much of it could of been helped, but I've notice my GM getting upset at Jon(my other manager) and then becoming upset at me if he happened to show up to watch a movie. Today we got our schedule for next week and me and Jon have total opposite schedule if I'm working he's off and if he's working then I'm off or I come in and he's off. Yesterday me and jon open together and my GM came in on his off day to see someone in and finish up schedule? Which that normally doesn't happen seeing we have 2 more gm and he can do it all from home, then he followed jon for about 10mins not talking at all but what grounds does he have to not schedule us together? And do I have a right to know?