Dr. Yamanako's Maid #12&13 (Pixiv Fanbox)

"I believe that a slave's most valuable asset is her mouth. Of course a moist pussy and tight anus is also quite useful, but it does not have nearly the...versatility...that the oral cavity does. For instance, it can be used to clean toilets, pleasure cocks...I often even use them in the training of my shotas in the fine art of face fucking. It can even provide saliva to lubricate strap ons for future penetration, as you can see here" -Dr. Yamanako