Start by giving your apprentice a morning fuck

The following morning you wake up with Doe lying closely next to you. You first rub your eyes then gently pet her ears while she sleeps. Doe flaps the ear you are playing with, then opens her eyes gently and smiles at you.
“Good morning, sweetie.” She says.
“Good morning, my love.” You reply.
“I had the most amazing dream.” She says.
“What was it about?” You ask.
“I dreamt I was a soul.” Doe explains as she rolls on her back, exposing her breasts to you. “Then I was split in two. One half of me went into my body and the other half went into you. Then we met and I was complete again.”
“I use magic to keep myself young.” You explain. “I am far older than I look so I doubt I’m your other half. But I agree the idea is nice.”
“Or maybe your half got into a body right away and my half floated around a bit longer before finding the right one.” She says after which she holds her arms above her head and stretches.
You watch her chest rise and can’t help but run a finger along her nipple.
“It would certainly explain why I feel complete whenever I feel your sperm flood into me.”
“I see. So you were just fishing for my sperm.” You tell her.
Doe tries to smile innocently, but the not so innocent request makes it feel fake.

Regardless, you throw off the sheets and swing one leg over her. Once you are seated over Doe’s chest you place your dick between her tits. Doe puts her hands on her boobs and pushes them together. After she traps your dick in her cleavage you start fucking it. While you fuck her boobs, Doe looks down and sticks out her tongue. Whenever your tip gets close enough she laps at it. When you feel your tip is wet enough with saliva you pull it from between her tits. Then you press the tip against one of her hard nipples and rub circles around it. Then you move it over to her other nipple and slap the tip against it a few times. Then you go back to fucking her boobs.
When you are about to cum you cast a spell on your balls to make them overproduce sperm. Just before you hit orgasm you pull back and then release a torrent of sperm. Doe squeals in surprise but then just lies back and lets you soak her face and boobs in your sperm. When you are done, she needs to rub the sperm off her eyelids before she can see again.
“Eeeuw. It’s in my hair.” Your apprentice complains.
“Hey, you said it makes you feel complete.” You quip.
Doe laughs loudly, then puts her hands on her cum-covered boobs and starts massaging them.
“I shall rub it into my skin then.” She says.