To dream of incestuous practices, denotes you will fall from honorable places, and will also suffer loss in business.
This could be an extremely disturbing dream, but it does not necessarily have anything to do with sex.
It is possible that you may be worried about other aspects of your family life. If this dream persists, you may consider talking to a professional about it.
If you are currently making important decisions, don’t do anything that is morally questionable because you are already experiencing disturbing dreams associated with taboos that bring up feelings of guilt and shame.