"Papy, sweetheart, are you almost ready?"
"Yes, Metta, just a minute!" Papyrus called back. He looked himself over in the bathroom mirror and straightened his shirt before coming out. "What do you think?"
Mettaton smiled at the sight of Papyrus's green, white, gray, and black striped T-shirt, representing the agender flag. "You look lovely. How about me?" He gave a twirl, sending the edges of his own transgender pride tunic shirt flying out in a perfect circle.
Papyrus caught him and took his hands, holding him close. "Beautiful. But then, you always are."
They touched foreheads, grinning giddily. "You know, I'm so glad to be going to my first march with you," Mettaton sighed. "We get to be proud together!"
"Yes! Although I'm quite surprised that humans need such things in the first place," Papyrus mused. "It's… interesting how humans can behave over each other's identities… I wish they'd just accept each other and be nice."
Mettaton put his arms around Papyrus's neck. "Me too, darling. But they don't, so we have to show them that no matter how much they dislike us, we're here, we're proud, and we're not going away anytime soon."
He pulled back and picked something up out of a bag. "Here, have a rainbow flag."
Papyrus smiled and took it, waving it around a little, crossing it with Mettaton's own gay flag.
They held hands again. "Shall we join the others, my prince?" Papyrus asked gallantly.
Mettaton laughed. "Lead the way, my royal knight!"
They headed outside where a number of their monster friends and one small human child waited, all wearing polychromatic striped shirts or holding flags representing many different identities. Undyne, Toriel, and Lulu wore pink lesbian pride shirts. Alphys and Sans wore bisexual colors. Grillby had a rainbow shirt. Asgore had a pansexual shirt. Flowey had a transgender ribbon tied around his pot. And Napstablook and Frisk were proudly waving nonbinary flags.
"Come on, slowpokes, let's get going!" Undyne called. "We don't wanna miss the whole thing!"
Frisk took Toriel's hand and then Mettaton's, and together, the group moved off to join thousands of people in celebrating a beautiful part of their identities.