Light magic, the same one you majored in

“I’d like to learn more about the magic you are using.” Doe says.
You shrug and say, “Light magic it is, then.”

Since she already knows a simple illumination spell from earlier, you decide to continue with that. First you teach her how to make a ball of white light. While some of the more advanced illumination spells can burn, this one does not. You then guide her to make the ball float in the middle of the ceiling. It takes all her concentration to keep it going, but she manages.
While she is looking up at her magic ball and focusing, you take the time to sneak a peek at her chest. If you tell her to, she will bare her breasts for you. She already told you herself. But asking her right now would break her concentration, so you let it slide.
Then you show her what a master light mage can do by casting this spell multiple times. You also keep the illuminative balls going without focusing any effort on them and then with a snap of your finger, all of them extinguish.

Next you teach her how to cast a beam of light. You also tell her that your teacher felt it was only useful as a flashlight. Then you explain to her how wrong he was and how it can also be used as a weapon. Simply cast it point blank at someone’s face and he will be blinded for a while, giving you the perfect opportunity to take him out. This spell has saved your own life multiple times and will be useful to her.
It takes her a just a few tries to learn the base spell. Then a little more to turn this ‘flashlight-spell’ into a high powered version. Maybe it is because of your expert advice, her intelligence, her passion, or all of the above, but she is learning magic very quickly. Much faster than you, at least. If you’re not careful, she might one day surpass you.
While she practices you find yourself studying her posture. Especially her hind quarters. The skirt she wears hugs her hips tightly, leaving few to the imagination. Her tails also make her skirt ride up a little. Just a little more and you can see her butt. Honestly you wouldn’t mind raising that skirt of hers and slide your dick inside her …

You stop yourself. Did you really just think about having sex with Doe? She is your apprentice! And before your test subject! How can you be thinking of having her at your mate?

“I think I’ve got the hang of the spell now.” Doe says as she twirls to face you.
“Great. You’re making a lot of progress.” You compliment her.
Doe smiles and blushes.
“Doe,” You ask with a more serious tone. “How was your life before you became my prisoner?”