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.
It's like coffee and milk! That's a great couple. How the kid managed to stick it in such a pussy and gently fuck it and not hard, I don't even know.