He tries sending her back.

Occultism Lesson #1: "Occult beings are thoughts and feelings actualized."

Easy enough to grasp. Anyone who practices Occultism knew that. Alan had undressed his fiance with his eyes enough times that it turned real when he tried an occult summoning. Annoying and embarrassing, but nothing he couldn't comprehend.

Occultism Lesson #2: "When bringing something up, be absolutely certain you can put it down."

Also easy. Alan has studied enough of the fundamentals to do just that.

He just had to send her back to the void that spawned her, his family didn't need to know about it, and he can try again tomorrow.

"What's that?"

Alan nearly fell on his face. While he had been flipping through his book for the banishment section, the succubus had snuck up from behind and was now looking at his book over his shoulder.

"What the? Why aren't you still in the circle? It should keep you there?"

She put a finger on her pink lips before shrugging. She hadn't been standing behind him, but rather she was floating like a koi fish underwater, giving him just enough to see down her cleavage and the heart-shaped curvature of her buttocks. He also realized that she had a long tail that came from the base of her spine and ended at a spade, and her dark hair hid a pair of curling horns that he mistook for a pair of elaborate pigtails.

He then looked down at his feet. All properly drawn summoning circles were sketched out in either dark or light chalk. Then, you would surround that circle in three different circles, one made of salt, one of ash, and one of pulverized bone. He then realized that his shoe had accidentally brushed against the bone circle (having made of cow-bone available at any apothecary), breaking the binding meant to keep the occult being's corporeal form in place. The salt and ash circles were still in-tact, which should ensure that she won't act with any potential physical or magical attacks on his mind.

She wrapped both of her arms around one of his.

"What'cha doin'?"

"Uh... I'm looking for a banishing ritual."

"What's that?"

"It's a way to send you back to whence you came."

"Oh. Okay."