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!
In general, I understand the man - women are so good to bring the brains out, that I sometimes want to have a friend so hard to fuck! The most interesting thing is that his girlfriend liked it and she suggested that sometimes for a change in the relationship to apply such a role-playing game!