Why does a brother need a woman when you can ravage your sister in the throat

This brother doesn't care that he doesn't have a girlfriend. He doesn't even worry about it, because he doesn't need to, because he has a wonderful young sister. And if his brother needs to get off, he tells his little sister, who at the same second strips naked and kneels down and lets himself be fucked in the mouth until his beloved brother poops all over her face.