If your brother (or anyone else's) has convinced your parents (or anyone else's) to leave them a greater slice of the pie, it will be too late to challenge it when your (or anyone else's) parents have passed away. Its not unusual for parents to favour some siblings over others ..... that in itself is not extra-ordinary before the courts, whereas any suggestion of "sweettalk" is mere heresay or methinks a figment of paranoia.
My advice is to enjoy them while they are still alive, and forget about the divvy. They should be priceless ... worth more than any inheritance.
