You could always bail out and say that the farmer is pretty select about who is allowed on his property with you, but I think the straight up approach that you're planning is always going to work better :)
I was feeling really nervous reading about hunting in full camo with your friends, yep definitely want to know exactly where everyone is at all times x_x
I think the direct approach is the best, I prefer to be open and honest as being otherwise often comes back to haunt.