As a long time FW vet, I know nothing about helio regs. I have no difficulty with anyone operating a helicopter from a field, but don't you have to have CAA certification, fire cover, etc?
I agree with those above, who suggest a friendly chat expressing your concerns and reservations (best on neutral ground - your local pub?). Much better to have an amicable solution than years of neighbourly hostility; it should work, considering you're both pilots...