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.
I can see it's not the first time they've had sex together. It's so convenient - you don't have to take anyone off, there's always a shower and a bed nearby. Of course, her brother's dick is great, so any sister would fall for one and suck it at the first opportunity. Well, it seems to me, he doesn't mind having fun with his sister with it either - his own soulmate won't betray him or make him marry him. It was so cute when her brother came inside her - it just cheered them up. )
I would fuck her...