The son + Chloe
Why did they get it on?
sharePerhaps she was horny or it was purely out of revenge... that was the best scene in the film.
When there's hopelessness, people revolt. - Tupac
No, it was the son who was horny, not Chloe. Chloe was clearly lesbian and only had her eyes on Catherine. What she did was not purely out of revenge either. As she said again and again, she saw something definitely belonging to Catherine in the son.
In this sex scene, Chloe was on top of the son – just as she was earlier when she had sex with Catherine. The boy shouted more than once: "Look at me!", but we see that Chloe continued to turn her face away, and that she was in fact looking at Catherine's shoes on the shelf. She was obviously imagining that she was having sex with Catherine.