The guy is lucky with his sister - she is a nipple. She's ready to open her mouth for him to stick it in her. Apparently she serves him regularly, because he no longer feels affection for her, but fucks her like a street whore - rough and bold. However, she seems to like this treatment.
For that matter, I'd rather have her in a 69 position, it'd be more interesting for both of us! By the way, she did a good job on the cock, too. Probably imagined herself as a cowgirl, and her shoes as spurs, which she used to ride the stallion! When she laid down on her side, her shoes disappeared, so the ride was over? Apparently the movie was filmed in several stages, and we naively believe that the male is so hardy and can fuck a lady for a long time and not cum!