There is no one else and he has to fuck his little sister
His tribe is getting smaller and smaller and that, along with the constant threat of the tigers that want to eat all the men, greatly complicates his life. At this age, he should be married, but he does not have the dowry to achieve it and also, he has to stay at home taking care of his little sister. Right now, she wants to fuck and there is no one else who wants or can do it. Then he has to take out his cock so she can make it hard and then penetrate her pussy. It’s sad but a man has to do what he has to do. It is the life of a man.