Lady Eva wants to humiliate her slave by making him inhale the smell from her sweaty, stinky boots. She wants to make sure that he smells nothing but her sweaty feet so she ties her sweaty boot to his face. He is forced to breathe in the stink and she adds to his humiliation by demanding that he polish the dirt and sweat with his tongue while the boot is on his head.
When she goes to the bathroom, she knows she will have to fart. She is happy to call her slave into the bathroom and start to fart. She expects her slave to stand with their face in her ass, smelling as she farts. She wants them to leave the bathroom with a fresh batch of her odor deep in their body. When she knows that she has to shit, she makes them stay in the bathroom to smell her funk too.