Emily went about her day with an unusual energy. She quickly completed her weekend chores and homework, and went for a long jog. She'd been coasting along so well she'd practically forgotten about what happened that morning.
It was after dark when Emily heard a soft knock on her window. She looked over and saw Brian standing there, and suddenly she remembered what had happened. Emily locked her bedroom then unlocked her window and let her neighbor in.
"Hi Brian, what brings you over?"
"I seem to be missing some clothes" said Brian with a wry smile. "You wouldn't happen to know anybody who snuck into my room this morning and took them, would you?"
They shared a laugh.
"That must have been weird for you. I don't normally wake up as a sex demon."
"Too bad - I was hoping it wouldn't be a one time thing."
"It was fun. I wouldn't mind doing it again, even without being a succubus."
"How about right now?" Brian suggested.
Emily needed only a moment to consider. "Okay!"
They kissed, tentatively at first but soon more aggressively. Hands began to roam over bodies and soon their shirts were off.
"You have magnificent tits" said Brian as he took a breast in each hand and caressed them.
"Normally they're not as impressive. It seems to be a lingering side effect from my transformation this morning. Not that I mind."
"Neither do I."
Brian sat on the edge of Emily's bed and she climbed onto his lap as they continued to make out, grope, and grind. Emily as feeling hot. Not just normal horniness, but like she had felt that morning. Brian's hands were on her ass, under her shorts, when she felt his finger touch something else.
"Your tail is coming back" he said.
Emily didn't feel any surprise at the revelation. Her lust and sexual hunger were growing, and now her tail was making her shorts uncomfortable. She dismounted and removed her remaining clothes and felt her tail sway freely. Then she felt horns push out of her forehead. And something more, as her body convulsed and leathery wings burst from her back.
She had not only transformed again, but further this time. And here was Brian, willing and eager again. She licked her lips with anticipation and discovered another change: her tongue extended much longer than it had before. Emily knew just what to do. Pulling off Brian's shorts and boxers, she spread his legs and dropped to her knees. The succubus didn't hesitate to wrap her sinuous tongue around the erect penis before her, taking it into her mouth. Brian quickly learned pleasure beyond his wildest dreams. Desperate to hold on longer, he grasped Emily's horns. She knew he was cumming soon if she didn't use her inhuman skill to draw things out. Emily could, but didn't want to; she was hungry and went deep. Brian climaxed, pumping and pumping to Emily's delight.