Mmmm! I love the hard and excited glans being slapped. I start to feel really horny looking at you, pet, let me to take off my skirt.
Im sure that you prefer that method of give the anatomy lessons than the method of the old Teacher Anne, sure?
Take the ruler, pet. We will start focusing on your left testicle. How it feels, tied really hard and separate of its twin?
Lets start with 10 soft slaps of the ruler. Tied and excited im sure that even the lightly slap causes a lot of pain in your testile.
Another 10 slaps, a bit harder than the previous.