I am having massive problems with my brother in law right now but have gained some quite significant leverage more than likely can not be used without serious ramifications. So I am looking for advice.

Basically the story goes: -Mother in Law got pregnant at 16 to some dude, made my poor father in law marry her, poor bastard raised this guys kid.

-Brother in law works out his daddy isn't who he thought he was starts hanging out with his biological dad maybe even starting a business together

-Brother in law starts fighting with his mother she loves the pain meds gets high and tells me in not so many words the truth.

-The Bastard decides that now he doesn't really have the right last name and to approach his grandfather (sucking up and manipulating) to buy the family farm cutting his father and uncle out of the inheritance. I guess before to many people find out.

-There's a massive amount of nasty history between him and I but to this point I have always been the better man. But I've just about had enough.

What do I do: -Do I tell him that I basically know all and if he doesn't pull his head in his reputation will be destroyed for being the lovechild of another man who stole the family farm.(big deal small town)

-Do I drop subtle hints like saying things like man you look like this guy I met (Aka his biological dad) and talk about cuckoos a lot.

-Do I tell him I know but say what your doing is wrong and reassure him that the outcome will be the same if you don't be a prick your still going to inherit most of the farm (Truth)

-Do I drug him and take photos of him with a ribber dick in his mouth and tell him that if he doesn't sell his house and leave that I will release the photos to your wife and she will believe you have been cheating on her with men.

-Do I seduce his wife and mother then rub it in his face that I have been with his wife, sister and mother.

-Legally I don't think I have anything if grandad sells that's his decision.

What do you think?