Short one shot I own nothing. Based on the comic where Mettaton tries to black mail Sans but it back fires. Sans/ Older Frisk. Also explains the 'Black Mail' incident from chapter eight of Anti Gravity.

Undertale © Toby Fox

~*~*~Black Mail?~*~*~

Sans stretched out on one of the many park benches eyes closed as he listened to everyone run around. He could easily pick out Papyrus' and Frisk's voices and smiled to himself. He peeked an eye open to look over to where the human was. Frisk was currently running from Undyne along with Papyrus as the ex-captain chased after the two with a spear. He shifted sitting up wondering exactly what he had missed in the few minutes he closed his eyes, as he was sure that everything had been fine when he laid down. He watched the chase and snickered as Frisk suddenly stopped and spun around and ran right past Undyne, throwing her off.

He glanced towards Papyrus who was leaning against the tree laughing, Sans smiled then immediately frowned as Mettaton rushed to his twin. He narrowed his eyes at the robot and pulled out his hand grabbing him with his magic and flicking his finger to the side sending Mettaton flying away from his brother who watched shocked and confused. Sans directed his attention back towards Frisk who suddenly let out a shriek and chuckled seeing that Asgore had caught the teen around the waist and hauled them into the air.

Sans grinned at Frisk when the human met his gaze and returned the wave Frisk sent at him. Frisk escaped Asgore and was suddenly in a game of tag with Kid. The two chased one another around the park a few of the others joining in. Sans couldn't help but feel a little bit of jealousy when he saw Kid and Frisk together, which he knew he shouldn't. The skeleton sighed leaning back against the bench, he didn't know how he managed to fall for the human. Sans shook his head and focused back on what was going on. Frisk was waving him over as he looked back over.

Sans blinked and stood, he took a step but paused as Mettaton walked over dusting himself off while picking leaves and twigs out of his hair. He looked up at the robot.

"Sans! I've had enough of this! I demand that you leave Papyrus and I alone!" he hissed.

"not gonna happen." Sans said, looking away.

"Yes you will, or else." Mettaton said. Sans looked at him, if he had eyebrows he would have raised one as he crossed his arms. Was Mettaton seriously threatening him?

"Are you threatening me?" he asked. Mettaton tensed but quickly recovered standing his ground.

"Yes! Because, as it now stands, I have the upper hand. I've recently obtained valuable information regarding your feelings for a certain human." The robot said grinning. Sans froze. "That's right! So if you don't give me and your brother space, I'll tell Frisk how much you really love them." Mettaton said. Sans turned and quickly made for Frisk. No way in hell, was that robot getting the upper hand. after this, he was going to make that robot regret trying to threaten him.

"W-wait! What are you doing?" he heard mettaton call after him.

"Hey, Frisk, come here for a sec… I… I got something to tell ya." Sans said. Frisk smiled, following him away from the others a few feet.

"What is it, Sans?" they asked. Sans rubbed the back of his head feeling his cheek bones heat up.

"..I.. I uh… really like you. I like spending time with you and our talks…. And.. I… Its great being friends but…" He shifted, oh yeah… Mettaton was so going to pay. "…I want to be more than just friends Frisk." he mumbled. This was not how he had pictured telling Frisk his feelings.

"R-really?" frisk asked.

"yeah. I… love you frisk." Sans smiled as he said the words, as soon as they left his mouth Frisk threw themselves at him hugging him tightly.

"I love you too, sans!" they said pulling back before kissing him. His eyes went wide, shocked at what was happening before wrapping his arms around the human and closing his eyes as he pressed back into the kiss. When they pulled away, Sans sighed in relief. Frisk giggled, and kissed his cheek.

"i'm so glad you feel the same way." Sans chuckled pulling Frisk closer.

"Frisk! Come on! Let's get back to the game!" Kid shouted. Frisk pulled away looking over to where the others were.

"Coming!" they called, they looked back at Sans. "Wanna join?"

"as much as I would enjoy chasing you around… I'm a little bone tired at the moment." Sans said, grinning as Frisk groaned.

"Talk you in a bit." they said before rushing to their friends. Sans turned and headed back to where Mettaton was watching worriedly.

"What did you…" Mettaton froze as Sans looked up at him his eye blazing as he grinned.

"What the fuck is up?" he asked.

"No!"the robot cried stamping his foot.

"What was that about black mailing me?" Sans asked, stepping towards Mettaton who stepped back.

"N-nothing." The robot squeaked out.

"That's what I thought." Sans said, his smile dropped and he stepped forward Mettaton stepped back and fell back on to the bench. "Don't ever try to threaten me again. This is strike 1." The skeleton hissed. Mettaton nodded gulping.

"Hey, what are you two talking about?" Papyrus asked jogging over. Sans stood straight and grinned at his twin, his eyes returning to normal instantly.

"Oh, we were just having a friendly chat about how nice it is here." Sans said.

"Uh… y-yes. It's very… nice." Mettaton said.

"IT IS NICE HERE!" Papyrus agreed.

"PAPYRUS! TRAINING!" Undyne yelled. Papyrus jumped and rushed over to the ex-captain. Sans watched, before giving Mettaton one last glare and moving off to snag Frisk by the waist the human ran passed him.

On second thought, maybe trying to black mail Sans had been the best idea that Mettaton had had. Maybe Sans would cut the robot some slack. Or not.

~*~*~End~*~*~

And that my readers is how Sans and Frisk became a couple. Hehe.