RE: piss me off
I would politely explain to the farmer the situation and how much the son in law screwed things up. I would explain to the son in law (in not so polite of a manner) how wrong it is to mess with someone else's stand when they have permission to hunt the land too. Then I'd try to work it out to hunt when the son in law wasn't there. If this doesn't work out, I'd find other land to hunt and not be available for chores at the previous place. I personally only hunt land where I have exclusive rights. This is not hard to do. Whenever a farmer gives me permission, I always ask who else hunts the land. If other people hunt the land, I thank the farmer and tell him I don't go on land where others hunt because I don't want to mess up their hunting and I don't care to have mine messed up. I have been given exclusive rights to more land than I could ever hunt myself and get other hunters to take care of the farmer's deer problems. All stay pretty happy that way. Good luck with your PITA.