RE: I need to whine a bit.
That's a tough one, but if you pay half for access to the entire 380, and your name is on the lease as such, then you have the right to hunt anywhere on it!!
I would try whatever possible, to not turn it into a fight, but you have rights too!!
If your talk with him doesn't work, maybe your sister can help him see that he is being unreasonable! Otherwise I'd just say, I'll stay out when your there, but if your not, I'm hunting there! Point blank and period!!
Why bother to pay for it if you can't hunt it?
My $.02!!