Terezi stared at the blood on her thumb, then down t the vile, evil beast that had caused it. A tiny, red hermit crab with a shiny grey shell looked back up at her with big, bulbous eyes. The stupid crab, dubbed "Crab" by her dumb step-brother who was too lazy or too stupid to name his pets, had viciously attacked her! All she had wanted was to get it in its shell so she could steal it and paint it bright red! It should be grateful that she was fixing up Karkat's shitty paint job. I mean, grey? Seriously?
Karkat, of course, chose that moment to walk in from school, which she had skipped to play this prank. He caught his step-sister in a glaring match with Crab, her thumb in her mouth. Inwardly he sighed, wondering what in the Holy Mother of Fuck he had done in a past life to deserve this. Was it because of that one time he'd actually managed to blow up Sollux's computer on purpose?
"Terezi, what in the name of Jesus, Mary, and Joseph are you doing?" He asked, eye lid beginning to twitch. "I've told you a thousand goddamn times not to come in here, you putrid, donkey fucking cockmunch!" He was shouting now, he knew, but the absurdity of the situation and the knowledge that Terezi had probably been up to no good was making it hard to keep his cool.
"Calm down, Karkles." Terezi snorted around her still bleeding thumb. "I didn't find your porn or anything." She rolled her eyes. "Now go get me a bandaid, your stupid attack crab bit me." She pouted, snarling at the offending animal as she finally pulled her thumb out of her mouth.
"First of all, I don't even think an attack crab is a thing. Second of all, he pinched you. Crabs don't bite." Karkat corrected, snickering a bit. "I'll admit, though, that does look pretty bad, follow me." He beckoned as he turned, heading down the hallway to the bathroom. Once there, he turned the sink on and gestured to his step-sister. "Here, wash the cut while I get the bandaid ready."
Terezi hissed as the cut came into contact with the water, watching the bright red blood wash down the sink. Yet another instance in which she found herself mildly regretting letting her girlfriend's mom perform that eye transplant. She washed the cut gingerly as Karkat put neosporin on a bandaid, drying it gently once it was clean.
"Hey, Karkat?" She asked as he applied the bandaid.
"I swear to god, Terezi, if you ask me to kiss it better, I am going to shove my foot so far up your ass that you'll taste rubber until you die." He hissed, eyes narrowing.
Terezi snorted and batted his hands away, finishing applying the bandaid herself. "No, asshole, I was going to ask you why you painted your stupid crab grey. You could have painted it any color, and you chose the most boring color in existance!" She mocked, giving a snort of laughter. "I guess it figures, boring pets for boring people!"
At that, Karkat looked a little bit uncomfortable, shifting from one foot to the other, unable to look at his step-sister. Terezi zeroed in on this reaction with interest, virtually smelling an embarrassing story she could hold over him later.
"Well, Karkles, you gonna spit it out, or what?" She asked, punching his shoulder lightly. "Or is it something embarrassing? Did ickle bitty Karkles have a crush on some super boring chick with a thing for grey?" She teased. When Karkat didn't so much as glare at her, she started to worry. "Hey, Kar, it's okay. Whatever it is, I promise I won't make fun of you for it unless you really deserve it." She assured him.
Karkat just rolled his eyes to the ceiling, muttering resignedly to himself. "Fine, but this does not, under any circumstances, leave this room." He growled. "Do you understand me, or do you need your ears fixed, too?" Maybe that had been cruel, but he didn't need this hanging over his head.
Waiting for Terezi's confirmation that she'd heard, he took a deep breath and something unintelligible. When Terezi gave him a puzzled look, she sighed heavily and repeated. "It's because I got him when you were still blind." He grumbled out. "If I had painted it some bright color, or with some design on it, it wouldn't even matter because the only other person who even cared that I was getting a pet was you and you couldn't even see it. So I just painted it grey." He shrugged at the end, as if it were no big deal.
Terezi was floored. Sure, people had made changes to accommodate her disability before, but it was usually accompanied by awkwardness or loud posturing so people could actively see how accommodating they were. Karkat had just...done it. She hadn't even known what color the crab's shell was until after the transplant.
"Well then..." She began, looking everywhere but at him. "He's grown a lot, hasn't he? Maybe he needs a new shell." She coughed, brushing dust off of her clothes that wasn't there and stepoing past her step-brother, out into the hallway. She was halfway through her doorway when Karkat grabbed her arm and yanked her back out.
He led her back into his room, leaving her at the doorway as he rifled through a drawer in his bedside cabinet. He pulled out a fresh, unpainted shell and tossed it at her. "What color?" He asked as she turned the object around in her hands, thinking.
Suddenly, she grinned and tossed the shell back at him, pulling out the candy red paint she had intended to use in her prank. "It just so happens that I have some paint right here we could use. That is, if you don't object to the color."
Karkat's eyelid twitched. "You were in here to paint Crab, weren't you?" He asked, exasperation evident in his voice. Terezi just laughed and snatched the shell away from him. "Fine, whatever. Just go get some newspaper from the kitchen so we don't get paint on the carpet. My dad would kill us."
"Aye, aye, Captain!" Terezi saluted jauntily, turning on her heel and dashing off to her task.
Thirty minutes and one small paint fight later and the bright red shell was drying on a shelf, the two step-siblings snacking on popcorn while Karkat tried to explain why his taste in movie wasn't shitty and failing. It was more fun than she'd had since her surgery and Terezi couldn't help but be glad for once that her mom had remarried.
Years later, when Crab finally died, Karkat gave Terezi the now empty shell. It sits up on her shelf between her wedding photo and her son's first handprint as one of the best memories of her teenage years.