Sans AU One-Shots

❀Killer❀ || monday. (HS)

Pairing: Demon! Killer Sans x Summoner! Female Reader
Prompt: It's the demons' heat week, and (Y/n) offered to help them out with their urges.
Type: smut
Length: 2.3k words
Background: This was in His Summoner (hence the HS in the title) as part of a spicy week-long bonus thing where each of the guys got a day of the week with Y/n to claim her. The goal of the heat week is procreation (i.e. making babies) and after mating, the heat urges go away. This is the only time Nightmare will let them have Y/n, so they better make it count. | Takes place on Monday - the first day of their heat week.
Notes: Poor Y/n (or lucky, depending on who you ask). Them being a demon only changes how tall they are (at/over 6'4"), their power (they're much stronger than humans), and how they see Y/n (among other things I explore in my full-length story that aren't relevant for this smut-shot). 

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(Y/n) wasn't entirely sure what this week-long heat would entail, but what she admittedly should've seen coming was Killer going all out. She wasn't sure where he got the rose petals or the rose-tinted lights, but she felt her heart race at the effort. He opened the door to the green bedroom at the end of the hall and gestured inside as he clutched a rose in his teeth, wiggling his browbones suggestively. Her face heated up as she took his extended hand, and he pulled her inside and shut the door. It was his day with her, and he was going to make the most of it.

"Do you usually put in this much effort for a female demon?" (Y/n) asked, spinning around in awe of how perfectly he'd dressed up the room. The twin beds were pushed together into a king with the gentle lighting making the bed look extra comfortable, and of course the rose petals decorated the floor and blanket. Killer himself was only wearing his shorts, and despite him literally being a skeleton, he made it look good. (Y/n) couldn't keep her eyes to herself as he led her to the bed.

"Not usually," Killer said with a smirk. He offered her the rose, which she took and sniffed. It smelled amazing, as did the entire room. "But this is a special occasion, darling~"

"So how do you usually do this?" She set the rose down on the nightstand beside the bed. For obvious reasons, she wasn't sure how demons in particular went about procreation—which is what their heat week was designed for.

"Same as humans," Killer said with a shrug, gently pulling her into his arms and tilting her chin up towards him. With the lack of space between them, she could feel him pressing up against her, and she glanced down curiously. There was a blood red glow coming from his shorts, and he chuckled. "Already trying to get in my shorts, darling?" Her face flushed red and she quickly shook her head.

"No! I, uh, just don't...how do you do it? You're a skeleton." She gestured to him vaguely and he smirked.

"What do you mean?" he asked, pretending to be clueless. He admired the way her face glowed from embarrassment as she glanced down at his shorts.

"Do you have, like...a dick?" The words were barely more than a whisper, and he smiled wider as he nodded. "How?"

"Magic." He winked. Her gaze flickered down again, and he leaned down to press a sweet skeleton kiss to her lips. He pulled away just far enough to smirk at her. "You can touch it, darling~" Unable to push aside her curiosity at his permission, she carefully slid her fingers around his shorts waistband and pulled them away from his hip bones. Attached to his pelvis was an anatomically accurate penis, blood red and glowing with magic like some kind of ecto-body, and despite how (Y/n)'s face burned with embarrassment, she was fascinated too. It really was magic.

"So do you make it specifically for intercourse?" She looked up at Killer, excitement glistening in her eyes, and his expression softened.

"Pretty much." Her wide eyes returned to his dick like it was the most amazing thing she'd ever seen—he wondered if she'd be thinking the same thing when it was inside her.