It's an interesting camerawork solution, with the camera inserts that the guys are holding themselves. You look as if through their eyes at what is happening and very realistically imagine your dick in one of the holes of the slutty brunette, though the overall picture is not lost, and there's a lot to see here: a beautiful girl caught, skilled. And the guys are lucky, and us, the audience.
Lady looks like a long time unsatisfied walks, if so easily with her son and daughter was able to go to such sexual intercourse, while she herself has inclined them to it. The son was not confused, noticing through the keyhole what the mother and sister were doing, decided not to lose the opportunity and joined in. Especially since he had previously looked at family photos and became aroused. It was a sin not to take advantage of the depravity of his family.
A guy let his girlfriend go to a rich mister. The black daddy offered her $20,000 to serve his whims for a month. What normal girl would refuse that? Any husband would send her to earn money - let her work her holes. After all, she's a chick.