Fraternal polyandry is a type of polyandry in which two or more brothers marry the same wife. All brothers have equal sexual access to the shared wife.
More About Fraternal Polyandry
Fraternal polyandry is contrasted with sororal polyandry which is the practice of sisters sharing the same husband. The practice is common in areas of the world where there are inheritances. In the case of fraternal polyandry, it is more practical to marry all brothers to one wife so land plots are not separated as would be the case if all brothers were married separately.