Borat's sister IS incest.
Borat:"this is my sister"
*Proceeds to eat out her face*
Borat:" she is no.4 prostitute in all of kaszakhstan. Nice"
Incest= Borat's sister
Borat:"here is my sister"
*Proceeds to eat out her face*
Borat:"she is no.4 prostitute in whole of kazakhstan.Niicee"