"UNDYNE," Papyrus chirped, "DO YOU HAVE ANY PLANS TODAY?"
"Nope," she replied with a bored look on her face and her chin cupped in her hand. "You?" She already knew he did have some, but if she didn't ask, Papyrus would keep trying to indirectly tell her to ask.
"NYEHEHEH!" Papyrus laughed. "OF COURSE I, THE BUSY PAPYRUS, HAVE SOME PLANS! MY BRO AND I ARE GOING TO GRILLBY'S!" He paused for a second. "YOU WANT TO COME?"
Undyne sighed, "Got nothing better to do anyways."
Later...
"HEY BRO!" Papyrus said as he entered Grillby's, which was filled with chatty customers.
"Heh, hey. You're late. Toriel's here too." Sans chuckled. He was sitting across of Toriel, who had just cracked a joke, and who he invited as a thank you for her pie.
Undyne sniffed the air. "Smells like something's burning."
Sans took his chance to crack a joke. "Maybe you're smelling your house!"
Papyrus screeched at his brother. "WHAT THE BONE, BRO, THAT'S SO RUDE! GIVE HER AN APOLOGY RIGHT-!" He stopped trying to get his bro to say sorry when he saw Undyne and Toriel laughing.
Sans looked over at Grillby after laughing at his horrible pun. "I want a burger covered in extra ketchup!"
Grillby nodded, then glanced at Toriel.
After thirty seconds of staring back at Grillby, Toriel realized he was "asking" what she would like to order. "O-Oh," Toriel stammered, "I'd like a hamburger, please."
"Fries and a burger," Undyne said.
"SAME AS UNDYNE!" Papyrus hollered.
About two to six minutes later.
"O-Oh. That's an..interesting grease covered burger." Toriel poked at her burger a bit.
"Would you like some ketchup with that?" Sans grinned.
"U-Um," Toriel stammered as she looked and poked at her burger, "no thanks.."
Everyone else also said no, well, besides Undyne. "Dang, this thing is as fiery as Grilllby's head. I think some ketchup would go nice with it!" She held put her hand and waited for Sans to hand her the bottle of ketchup.
Sans slid it over, but just as Undyne was about to squish the living tomatoes out of the ketchup with her harsh grasp, he pulled the ketchup bottle away from her.
"..."
Sans grinned widely at her, possibly in a friendly way, but to Undyne, he was challenging her.
"WHAT THE FISH IS YOUR PROBLEM?!" Undyne pushed her seat back, slammed her left hand on the table, and stood up with her eye gleaming with anger, and her head as red as fire.
"Woah there!" Sans didn't waste anytime using this as a chance to make a dumb pun. "Don't be so HOTheaded!" Sans joked.
Undyne couldn't help but laugh, because she had a terrible sense of humor according to Papyrus, who was currently screaming his skull of because of his brother.
Toriel finally tried her greasy burger, which was about ninety percent grease. Her face twisted into a disgusted one, but she attempted to compliment Grillby and find a good aspect somewhere in it. "So, Mr. Grillby, I, uh, enjoyed the burger, especially the, uh, grease..?"
All eyes were on Toriel. Then Sans smiled wider as he finished up his fifth burger with extra ketchup.
"So you like the grease?"
Awkwardly, she nodded while attempting to smile, but it ended up crooked.
Sans jumped up and poured extra grease on her burger, supposedly because he thought it was a nice thing to do. Toriel cringed at the now ninety-nine-percent-grease burger.
"Enjoy!" Sans beamed, and his grin widened.
Later...
"Okay, are you done?" Undyne asked.
"YEP!" Papyrus beamed. Everyone else was done too. Toriel had already left with a sick look on her face because she ate the whole burger and paid her bill, and Sans had offered to walk her home. As Undyne and Papyrus packed up, the idea suddenly came to mind.
"Who'll pay?" Undyne questioned. "Definitely not me!"
"..."
"Papyrus." Undyne spoke slowly as she gripped at his skeletal shoulder. "You'll pay."