I learned about this category from Trash Taste, but that's definitly what happend here.Domination Loss
Actually, back when he saw her playing with the dogs is when he desired to pet a dog, and because he's too scared to have any desires towards her herself, the reward was just him petting a dog, she just happened to be the only "dog" around for him to pet.Oh boy, you werent ready to be on the recieving end.
Yuuki is too subby to desire this, so i take it as the confirmation that the reward is based on the user desires. Not the slave.