Mistress Anni needed to have fun at the expense of her slave and she did it by cruelly teaching to be a foot slave. She had fun making him get scared of her and he wished that he had never met her as she had him do all manner of naughty and humiliating things. The mistress also made sure that the guy sucked her toes and was teased and denied.
This guy thought that mistress Anni was harmless. But she was not as he came to find out. The mistress cruelly tortured him and taught him a lesson. The mistress had him watch as she took off her shoes and then made him lick and smell her socks. They were stinky but that was the whole point. He had to do it all and there was no alternative for him.