My grandpa has a "no gay" clause in his will

So my grandpa and my father are farmers. I just came out to my parents and it went about as well as I could have imagined. They are some what supportive but not entirely sure what I mean. Their main concern is that apparently my grandfather is leaving the farm in a trust to my father; however, there is a clause that basically states that if any of his grandchildren are gay they will be cut out of the will. I'd be laughing at how absurd this is if it wasn't so real. This is a trust that is actually going to be legally upheld in court by lawyers once he's dead. Now my parents are scared that they'll lose the farm if he finds out I'm trans. I kinda planned on hiding it from him but apparently this could be for the rest of my life if his trustee also upholds this clause.

Now I'm stuck feeling like my choices are going to ruin my parents life and I couldn't have imagined this is how coming out to them would've gone.