Mistress Julia had a new slave and she wanted to make sure that she did whatever she asked her to do. So she had her lick her feet. It was a test and she got her to do it without much effort. The new slave was smart enough to do it without needing any force or being coerced. That helped him avoid being dominated in a worse manner. And it helped her avoid issues with the mistress.
This mistress is sexy and her trainer wanted to hit on her. But she was focused on her exercise and her gym training. She did not want to be distracted and that is why she had to punish him for the nonsense he did. She had to make him stay focused and that is why she chose to trample and dominate him until he learned his lesson in a cruel way.
This slave was horny and this mistress felt that she had to make him stop being horny. So she trampled his dick with her high heel boots. He was in pain and he was humiliated. But then again she remembered that it was not wrong to be horny. So she made it up to him by letting him fuck her leather boots. She applied lube on them and he fucked them good.