As you head out the flap of the tent in the Amazon basin a dozen children run up to you.
Instinctively you know they are yours.
You are the fertility goddess of this tribe. It is your job to produce as many children by as many men as possible.
The boys can not mate with their own woman until they have mated with you. It seems as though there have been many men that have mated with you since you became fertile.
Your breasts sag from the years of milk laden heaviness.
Your belly, while full and rounded now, would have no time to recover before it was filled with the next boy's seed.
Soon you would go into labor and the next man to bed you was the chiefs own son. Neither the chief nor his son were particularly good looking. But they were both extremely healthy. Oh lets get on with it they were fat. The most prosperous of the tribe were well fed and boy did you dread laying under that fat pig of a man. But that was your job.