This guy was so into madame Svea that she knew he was willing to do anything for her. And that is how she got him to try cum eating. She made him think that she had a thing for a man who ate his own cum and that is how the guy jerked off for her and he ate his own cum for her to be turned on like she had told him.
Madame Svea did not like how this guy behaved and she was pissed at him to the point that she had to punish him. The mistress felt that she had to degrade him and put him in his place and that is exactly what she did. He was shocked when she made him eat his own cum after she had forced him to use humiliating jerk off instructions to cum.
Madame Svea was interested in trying something new without her physically making someone do something. That is how she found herself making this guy eat his own cum. She made it look like a very naughty thing and one that would make her get wet. And she did this while she teased and flirted. The guy bought the lie and he did it as the mistress enjoyed seeing him do it.