Those who think it's not normal, think about it, these are strangers to each other. That's why there's nothing wrong with it. Two adults of different sexes are at home alone, hormones are splashing in both of them. So the skinny blonde was not at all against caresses from her stepbrother, she only broke down for show, but with his insistence his brother showed the seriousness of his intentions, and that this will not go beyond their bedroom. Both are happy at the end!
Everything in this family is through the ass - the daddy spanks the daughter, the mother sucks the son. And in order for the husband to fuck his wife again, she had to seduce her daughter. It seems that they themselves are already confused who fucked who, but nevertheless, everyone is in a New Year's mood and there is enough pussy for everyone.
I could see why the housekeeper kept her apron on till the last minute. If someone came in, she could have said she was cleaning the room and the owner's dick in her mouth was an accident.