Coupledom
The dominant couple have the slave sniff the lady’s pedicured toes. They don’t actually smell bad (and in any case the aroma of the beautiful, young woman’s cork, platform heels overwhelms the footslave’s nasal receptors) but still the pathetic slave is obliged to grimace by law at his degrading task – since the couple wish to know that he feels humiliated by having to sniff feet in public