When you have a hot ass like goddess Nika does, you have to show it off and that is what the mistress did. She wanted this guy to see not just how good it was, but also what she could do with it and that is how the guy went crazy over it and he wanted more from her but she did not give him what he wanted from her.
Goddess Nika had dirty socks and she turned them into a weapon to punish this guy. He had to realize that she was not going to let him get away with it and so she used them to trample him and when that was done, she had him lick them clean. He was shocked at what she asked him to do but he had no choice but to do it.