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"
Incest means having sex with someone from your family. This was a common thing back in the days but is not considered normal any longer unless you live in Alabama where it's still considered perfectly normal to fuck and marry your cousin.
Alabama person: so this is my wife Karen
Normal person: Ohh I thought Karen was your sister
Alabama person: Yeah she is my sister, but she is also my wife
Normal person: But that's incest
Alabama person: I really don't see the problem
Caucasian Aftivities
He/She/They committed incest with their sister in the pool