It is a sin to have s** with people outside of marriage and is considered prostituting your body. Your soul is meant for 1 partner, not to behave like a h*****. Even more of a sin to do to close blood relatives like sisters because it destroys love within a family by forcing them into a state of competition, jealousy and anger over one guy that is not even worth pond scum. Where the sisters are dumb is that you should never s*** where you eat, or in the same company that pays your bills, it is unethical and can get all of them fired.