A/N: Hello! This is my first fic and first… smut so please don't be too harsh but constructive criticism is welcome! This was actually salvaged from an old shitpost from one of my friends so if the ship is a little odd then that's why. I kinda made an entire au around this based on college which, while probably has been done before, has a few unconventional twists! Don't question Flowey's gender or body because even I don't truly know. Hope you enjoy ;)

It was a late Saturday evening and flowey was bored. They had been texting their boyfriend, sans, for a while and he said he might visit, but he was busy at the moment. They were in their bed, in a simple, pale green tank top and undies, looking at random things on the internet. Eventually they tired of the web and went downstairs to make themselves a drink. They considered themselves lucky that the found a relatively cheap 2 layer flat near their college. They were doing their A levels in, art, history, literature, and, ironically, biology.

Sans, on the other hand, already had a diploma in theatrical science, was teaching quantum physics in university, and is all round an academic prodigy. To his friends, this could have been taken 2 ways; on one hand, he's lazy, and they wouldn't expect him to put in the effort to learn something, but on the other hand, his father's W. , who is widely considered the Einstein of the monster world.

Flowey sat, waiting for the kettle to boil. They had considered getting a better kettle, as this one 'would take an hour to boil a teaspoon of gnats piss', but they never got around to it. As they heard the mechanical click they immediately picked it up and poured it into the pre-made cup of coffee mix and sugar. After stirring it a little, they immediately downed it, the smooth, black liquid barely being tasted.

They then walked back upstairs and fell onto their bed. After laying there for a few seconds they got up, grabbed a pencil and notepad, and sat back down. They continued their current project, which was a story about a wizard and a monster during the great human/monster war.

After around an hour of writing, flowey got up to go make something for tea, as it was getting late. They were about to walk out their door when a sudden flash of blue and something fairly heavy landed on them. After both of them came to their senses, flowey noticed that it was, in fact, sans who had landed on them. He had probably just teleported at the wrong time.

"Oh, Sans! are you ok?"

"Uhhh, yeah, mostly. Just a long day, is all. Sorry for falling on you."

"No no! It's fine, really." Flowey assured as they got up off the floor. They laughed at the awkwardness of the situation and sat down on the bed.

"Long day, huh?"

"Yeah, I just had to mark around 30 essays on the '~practical applications for quantum based computers~'. And I can only stand so much reading before I get tired to the bone." he explained, waving his hands in the air dramatically when he said the topic of the essays.

"Oh, that must have been as exciting as watching paint dry."

"Yeah, and then I had to make 2 blind teleports, one of which being over 5 miles! My fault, tibia honest, since I'd much rather mark while in my own bed rather than in an uncomfortable spinny chair."

"Ah, ok, but why not go home?"

"Your closer, and longer jumps take a lot out of me."

"And no other reason?" They smirked.

"Non at all." He smirked back.

"So you wouldn't want me to help… relieve some stress?"

"It depends, what do you have in mind?"

"Well maybe we can start with this." They said as they grabbed sans and began to kiss passionately, falling back onto the bed. Their tongues wrestled for almost half a minute before they pulled away. While they had been going out for around 6 months, it had never gone beyond this, but flowey had something in mind. When the kiss broke, flowey started to kiss sans neck. This slightly shocked him, but he got the idea. After a small while of that, they began to kiss again, this time rougher and even more passionately. They began removing each others clothing until they were both in panties and briefs respectively. Flowey, for rather complicated reasons, had a gender neutral body. They had a flat, breastless chest but also a vagina.

They began to kiss again, enjoying the feeling of skin against bone, petal against skull, and tongue against tongue. But eventually they had enough.

"Sans?" Flowey asked, breaking the kiss.

"Yes?"

"Do you w-want to… um…" flowey tried to ask sans, but was worried how he would react. It was all going so fast but they loved it, and wanted more, but didn't want to push him.

"I'm okay with it if you are, but if you don't wa-" sans tried to say, but as soon as he gave permission…

"Fuck me."

"Oh, ok then" he smirked as they flipped, sans now on top of flowey. They removed their final garments, and stopped for a moment to look at each other. Flowey was clean and smooth, as they don't grow hair, and sans magically materialised a glowing blue dick. Flowey licked their lips in anticipation.

Deciding to go slowly to start, sans eased into flowey, feeling just how tight they were. As he did this, flowey purred, loving the feeling of every inch bury itself inside. After his full length was sheathed, he began to pump slowly, eliciting more purrs of ecstasy. They began to pick up pace, flowey now holding onto the bedsheets.

"S-sans, wait-t a second." As they said this, they stopped.

"Is something wrong?"

"No no, I just wanted to change position, is all." As they said that, they flipped themselves over and got an hands and knees, with sans behind.

As they resumed, sans had a devilish idea. As he slid back into flowey, he made his ghostly dick bigger. As he did this he grabbed one of flowey's petals. This was the tipping point for them, as their petals were sensitive.

"Oh saNS! FUCK ME!" They shrieked, eyes rolling back. Sans obliged, continuing his dick growth until it hit their wall, and began pumping.

"Fuck me!"

He pumped harder

"FUCK ME!"

He pumped harder

"FUCK ME SANS! FUCK ME UNTIL I CAN SEE SHAPES!"

He pumped as hard as he could over and over. Their back arched as they felt the sense fucked out of them, there eyes rolling back into their head. Both of them shuddered as they finished in sync, and then proceed to collapse onto the bed. Flowey was out cold from shear pleasure. Sans put the cover over themselves and wrapped their arm around them.

"Good night, buttercup."