Well, the woman does not look like a naive fool, who does not understand why she was invited to a man's apartment! And by the looks of it, let's say she is not poor - dressed well and not cheap lingerie! Apparently just love to fuck and not against a little adventure with an interesting man! For this theory, and says strongly developed anus, which clearly sparkled when she was bent over.
Nice sister, I wouldn't mind a blowjob like that either. He came all over her face. I would have been brought to orgasm by such a blonde, too. In general, the filmmakers' incest was a good one.