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“Your lips are so red. Did something sting them?”
Leaning his upper body onto the floating dock while his tail stretched out languidly into the water below him, Midoriya Izuku stared up at his human friend in concern. She actually looked quite odd today. There were dark marks around her eyes that almost looked like bruises—but pretty—and her cheeks appeared flushed too.
The human, Ochako, smiled reassuringly at Izuku as she packed away the various samples he’d brought for her. Although Izuku had been collaborating with human scientists for a long time as he helped them study various types of fish, many aspects of their lives and behavior still baffled him. Like right now, for instance. How could Ochako be smiling so happily if she had such a vicious wound on her face?
“Don’t worry, Izuku!” she reassured. “It’s not a sting; it’s ‘make-up’. It’s a form of decoration that us humans use for our body, like clothes, tattoos, hair clips—things like that!”
“Oh!” Izuku smiled in relief, glad that Ochako wasn’t hurt. Decorating oneself was something he definitely understood.“What are you decorating for, then?”
“It’s my anniversary with Himiko!” Ochako shared. “We’re celebrating tonight.”
“Aww…” Izuku leaned his head on his hand, smiling up at his human friend. He’d met Ochako’s mate on a number of occasions. She had really sharp teeth, and seemed delighted whenever Izuku complimented her on them. “I bet she’ll love it! You look really striking, Ochako!”
“You really think so? Thanks so much! I usually don’t go for such bold colors, but Himiko loves red, and so…”
“Hmm…” Izuku’s thoughts drifted, his hand rising to touch his own lips. Like humans, a lot of mermaids enjoyed making themselves pretty, especially for their mates. Izuku usually didn’t pay attention to his appearance—he was too busy collecting and studying strange fish—but he and Kacchan had recently begun courting. And his birthday was coming up!
Izuku felt confident that Kacchan liked him no matter what he looked like, but he couldn’t help but wonder if something like brighter lips would enthrall Kacchan the way it apparently enthralled Himiko…
When he imagined Kacchan with bright lips, Izuku felt his heart skip a beat. He’d really love kissing Kacchan when he had such pretty lips, he thought.
As Ochako finished packing up the rest of the samples he’d gathered, Izuku decided that it couldn’t hurt to give it a try. Worst case scenario, Kacchan would just tease Izuku for engaging so much in human culture! That would be nothing new.
“Hey, Ochako? Do you have any extra dye that you used for your lips?”
It turns out that ‘lipstick’ didn’t actually work very well under water. That was okay, though, because Kacchan loved sunbathing, and so Izuku had already planned to take him to the beach for his birthday. There were a few nice beaches on their stretch of coastline, but for Izuku’s plan to work, they needed a little more privacy than the mermaid-and-human filled beaches they usually visited.
“Where we goin’, Izuku?” Katsuki asked, smiling at him through the sun-dappled rays that shone through the shallow waters.
“I told you; to your birthday surprise!” Izuku replied, squeezing his hand.
Katsuki’s birthday had dawned on a beautiful, warm spring day. A strong breeze the night before had blown cherry blossoms from the nearby forests into the ocean, and as Izuku looked upward, they created a canopy of soft pink stars to swim through.
Izuku had taken the time to set everything up at the beach in the early hours of the morning before he’d then gone back to pick up Kacchan, still sleepy and a little grumpy as Izuku snuck into his den to cuddle with him a bit. They had been courting since practically childhood, but had only recently made it “official”, so some things were still new…
It was that newness that made Izuku feel a little nervous as they finally approached the birthday surprise. When she gave him the lipstick, Ochako had told him about some of the things it could be used for, and Izuku would be lying if he said he wasn’t eager to give them a try.
Finally, they approached the sloped sandy shore of the beach. This beach was located behind some rocky hills that the humans hadn’t developed yet, so it was hard for them to access. Sure enough, when Izuku popped his head out of the water, he saw that they had the entire stretch of beach all to themselves.
Grinning, he pulled Katsuki to the spot he had selected, marked with the quilt of kelp he’d placed that morning as well as the bags containing their lunch, weighed down with rocks and swaying gently with the tide.
“A picnic?” Katsuki asked, failing to hide his smile as they approached. “Really, Izuku? That’s so cheesy…”
Kacchan loves it!
Izuku preened as they swam into the shallows, their fins breaking the surface of the ocean and their bellies grazing against the soft sand below them. He’d thought long and hard about how to celebrate Kacchan’s birthday, but in the end, Kacchan liked simple and thoughtful gestures. He wasn’t one for flashy or ostentatious acts of courtship.
They swam up to the woven kelp blanket, pulling themselves halfway out of the water. Izuku admired Kacchan for a moment as he pushed his wet hair back, immediately turning to bask in the springtime sunshine.
Katsuki was always beautiful, but there was something about the way his face relaxed, or the way he laid back, comfortable against the warm sand, that Izuku just couldn’t get enough of.
For a few hours, they laid against the sand together, talking and idly eating their way through the picnic—filled with all of Katsuki’s favorites, of course. Izuku gave Katsuki his other (less risky) presents, which he seemed to really like. In particular, he put on the corded bracelet studded with sea glass, and seemed to have a fun time admiring all the different colors in the light.
After a few hours, they dipped back into the water to freshen up and chase fish through the shallows for a bit, before eventually coming back to shore.
It was then that Izuku decided he couldn’t be a scaredy catfish any longer.
“I have one more surprise for you,” he admitted. A little pink in the cheeks. Katsuki turned back to Izuku curiously.
“Hmph. Didn’t I tell you not to overdo it, nerd?”
“I haven’t!” Izuku denied. “Well… This one isn’t like the other ones, anyway, okay? But I need you to close your eyes.”
“Hmm…” Katsuki eyed Izuku skeptically for a moment. Izuku fidgeted, nervous under the sharp red gaze of his partner and best friend. “Alright,” he agreed, closing his eyes.
Izuku scrambled for the lipstick, a bit surprised by Kacchan’s easy acquiescence. He’d expected Kacchani to put up a bit more of a fight… but the smile playing at the corners of his lips indicated that he was more amused by the request than anything.
Izuku pulled out a hand mirror and uncapped the lipstick. He had taken out the tube to examine it before, but now that he was faced with actually putting it on for Katsuki, he felt a little intimidated. It was much more solid than he’d initially expected—having thought that the dye might come in a powder or maybe a liquid—but this was more like clay. Ochako had said that people kissed with lipstick on all the time, but what if Kacchan thought it was gross? What if it felt clingy and weird? Or what if Kacchan thought it looked gross?
…It was too late to back out now, Kacchan was waiting. Izuku lifted the make-up to his lips, watching himself in the mirror. The first stroke of the lipstick put a vibrant strike of red across Izuku’s lips. He blinked at himself in the mirror, rubbing his lips together. The texture wasn’t bad, he decided, and the red stood out against the green in his eyes and scales. He applied a little more, being careful to outline the full shape of his lips.
When his lips were fully coated, he capped the lipstick and took a moment to examine himself in the mirror. His hair was drying into soft ringlets, and his cheeks were flushed from so much time spent in the sun. Most of the scales around his eyes and temples were green, but the few red ones sparkled, seeming to stand out more with the help of the lipstick.
Izuku turned his head, examining himself from different angles. He felt… pretty. Really, really pretty. Tucking a strand of curls behind his earfin, Izuku put the lipstick and mirror away. He turned back to Katsuki, still laying against the beach, patiently keeping his eyes closed so he wouldn’t spoil the surprise.
Izuku scooted closer, reaching for Katsuki’s hands. He felt like jellyfish were swimming around in his stomach.
“...Okay, Kacchan… You can open your eyes.”
Katsuki did, squinting for a moment against the bright sun, then focusing on Izuku. His eyes widened.
As Izuku watched, Kacchan’s pupils expanded, filling to eclipse his seashell red eyes until only thin rings of color remained. Izuku felt his second heart skip a beat.
Kacchan thinks I’m pretty.
Slowly, Katsuki brought a webbed hand up to cup Izuku’s cheek. Izuku pressed into his touch, smiling.
“I know it’s a bit of an unconventional gift but…”
Making oneself pretty is a very traditional step in courting.
“S’nice,” Katsuki said. “...You look nice, Izuku.”
Izuku giggled, turning into Katsuki’s webbed hand. He pressed a kiss to the center of his palm. When he pulled away, a bright red mark in the shape of his lips was left behind.
“Oh,” Katsuki breathed, looking at it with wide eyes. Pink spread across the translucent scales on his cheeks.
Another step in courting is to leave marks on your beloved.
Izuku giggled, biting his colored bottom lip with a fang. That definitely wasn’t a bad reaction. Feeling bold, he took Katsuki’s face in his hands and turned his head so the sweet expanse of Katsuki’s cheek was his to kiss.
Kacchan’s cheek was soft and warm under his lips, and Izuku used the excuse of the lipstick to linger a little longer. After a few seconds, though, he pulled back, eager to see his mark.
“It’s a human tradition to give one kiss for every year older someone turns on their birthday,” he said, pressing another quick kiss to Katsuki’s other cheek.
The new mark was sharp and defined. An imprint of red against Katsuki’s perfect skin. Izuku’s nerves buzzed with excitement as he examined the mark— his mark!— on Katsuki. Unable to contain himself, he ducked down to kiss him again, then again. He kissed his cheek again, his neck, his collarbones, smiling all the while.
Three, four, five…
The last kiss he placed (against Katsuki’s shoulder) looked a little fainter than the rest, so Izuku took the lipstick back out, uncapping it to reapply. When he caught Katsuki’s expression, though, he paused.
Katsuki looked up at Izuku, his lips downturned into a frown. He’d brought his tail up to wrap around Izuku’s and pull him closer, though, so Izuku knew he wasn’t actually upset. Most likely, then, he was pouting.
Izuku smiled, bringing the lipstick up to re-coat his lips.
“What’s wrong, Kacchan?” he asked. “Do you not like it? Maybe we should rinse off—”
Katsuki’s tail wrapped tighter around Izuku’s body. “Don’t you dare,” he hissed. Izuku did his best to fight down his grin, but knew that he was failing.
“Then what is it?” He brought a hand up to play with the fins around Katsuki’s ears. “You don’t like the color?”
“Dummy!” Katsuki scolded. “You’re doing the human tradition wrong!”
“Oh?” Izuku asked, suddenly a little flustered. “How am I supposed to—”
Katsuki ducked down, claiming Izuku’s lips in a kiss. Izuku’s eyes widened, then closed. He kissed Katsuki back gently. Their lips separated with a soft smack.
Izuku looked down at Katsuki with half-lidded eyes.
“Supposed t’kiss me here…” Katsuki murmured.
“Oh, I see,” Izuku giggled. “My mistake.”
Six, seven, eight, nine…
He kissed Katsuki until the bright red stain was shared between them, and stopped bothering to count when they reached Katsuki’s age.
Ah, well, Izuku thought, smiling into the kiss. The tradition didn’t say you had to stop if you didn’t want to.
When Katsuki turned his head to kiss Izuku’s cheek, Izuku basked in the feeling, knowing that Katsuki had just marked him with the lipstick, too.
Humans have pretty good birthday traditions, he decided.