Harsh but coupled with a certain joy in watching her pleasure! Jealous and grateful! Her body is his....she is giving her self to him and taking in all the pleasure she can take from him! But when she opens her eyes and looks at you, standing there in your frilly panties, your little tiny clit caged and tucked away, your breathless excitement as you watch him take her! As you look into her eyes you see that you are still the one she loves! At the end of the day he's leaving and she's cuddling next to you! That's love!!!!!
If you are watching be prepared. She will say things to him you might not want to hear and some will be like a kick in the gut. This I know for a fact!
i'm used to seen my wonderful Wife and Mistress very often this way ... and it uses to give me my own very sissy satisfaction since i perfectly know how fulfilled She feels! Just like it did watching most of my previous Mistresses - including my very first One.