Mistress Lana needed to torture and degrade this guy and she did it with her feet. She had to ensure that everything went according to plan. That is why she chose to make this guy lick her feet and do all other crazy things she wanted. The guy had no choice but to do what the mistress wanted. It was super fun for her and she loved it. She also got her message across.
Mistress Elena wanted to find out whether this guy was good at licking feet. She wanted to know whether he was so that she could get him to be licking and rubbing her feet. That is because he had said he had a fetish for sexy feet and she figured it was going to be something mutual for both of them. And she was right as he turned out to be good and they both enjoyed it.
Mistress Fox wanted to humiliate her girlfriend for disappoint her and she did it. She did not feel bad about it because she had warned her before. Now that she did not heed her warning, she had to suffer the consequences. She snapped and she told her to lick her socks and her bare feet to humiliate her. It was humiliating for her but it helped her to teach her a lesson.
This guy wanted to lick mistress Karina's pussy and she was not sure he was worth giving her pussy. She wanted to find out how good he was so she asked him to lick her feet for her to tell how good he was before anything else would go down. She was impressed with what she saw and she agreed to give him a chance to lick the real thing.