There's this thing about Kacchan. He can easily guess what Deku was thinking in a matter of a few seconds just by reading his body language. It's both a useless and a formidable skill.
Kacchan noticeably tensed up, his hands clenching tightly on the Captain America-themed comforter. Usually, this was Deku's cue to be careful because he's going to flip out anytime soon. Instead, he inhaled deeply and closed his eyes.
"So what do you remember?"
Deku blinked. "What?"
"From yesterday," He said impatiently.
"Uh…" He scratched the side of his face. "We were studying at the café yesterday and Shigaraki--Oh."
Something lit up in Kacchan's eyes at that moment. Deku wasn't sure what it was back then, but now he knows: it was hope.
A sliver of hope that will soon break apart like just like a fragile piece of glass.
"We… fought. Shigaraki-san invited me to go party with him. And I was so mad at you so I agreed. I went to our meeting place and he left me with Toga-san, where she forced me to drink this disgusting orange juice again and again until… Nothing. I can't remember anything after that."
"You…" Kacchan scratched the back of his head, feigning annoyance but there was a tinge of something else in his voice. It was hurt. "You know what, you're not allowed to drink any alcohol anymore. I think if you continue this, it's going to be a running gag where you black out and conveniently forget things."
"Conveniently forget things…?" Deku repeated. "Did anything…?"
"You got sexually assaulted by that Toga bitch," Kacchan growled, the former mirth in his voice disappeared completely. "Good thing I came to pick you up, God knows what she could've done to you if no one intervened. Heck, I bet that Shigaraki asshole knew what that bitch wanted and he left you with her on purpose--"
"Thank you, Kacchan."
That made him stop ranting. Katsuki clicked his tongue and looked away. "Why are you thanking me? It's my duty as your friend to take care of you."
"A friend, huh?" Deku absentmindedly muttered.
Kacchan acted like he didn't hear anything.
"Thank you for always being my hero, from back when we were kids up until now." Deku grinned, though it looked more like a wince in his current suffering.
"That's so gay," Kacchan rolled his eyes.
Then he froze.
His face burned crimson.
He crouched down on the floor, covering his face while incessantly screamed curses.
Midoriya's sweat dropped on the comical display before him. "Is there something wrong?"
"I… I just remembered something." Kacchan stood up, sitting back on the Deku's bed.
"Is it a good thing or a bad thing?"
"I… I don't know, fuck you, Deku, for being a forgetful bitch! Don't fucking drink if you can't hold your alcohol!"
Here it goes, Kacchan's regular mood swings.
"But seriously, did I do anything weird?" Deku couldn't help but ask, seeing his friend's reaction. "This is my first time to get drunk and I don't know what I'm capable of--"
"I won't tell you."
"What?"
"I won't tell you." Kacchan angrily repeated. "I hope this forever haunts you that you did something stupid and everyone knows about it but you can't remember it because you're a dumb fucking idiot who doesn't know how to drink responsibly.
"What do you mean everyone knows it?!" Deku shrieked. "What the fuck did I do?!"
And until the end, Kacchan didn't tell him. Maybe it was vengeance or just plain embarrassment, but either way, he knew that if he told Deku about what happened last night, things will change between them. Kacchan might be tough exteriorly, but he was weak and fearful inside. He was not ready to see if the change was negative or positive.
And he's not willing to find out.
Ever since that day, Kacchan seemed… softer. Of course, not literally because he had bulky muscles so prominent it's noticeable even if he's wearing a layered winter outfit.
He seemed… like he was always trapped in a trance with this small smile and a happy aura. Every now and then, Deku would catch him staring at him with this warm expression on his face, like he was watching a puppy catch its tail. But when Kacchan realized he was caught eyeing his best friend, he would turn into this bright tomato and swear at Deku as if he was the one that got caught red-handed.
Kacchan was also more into skinship lately. At first, it was just harmless rubbing their arms together, and all that shit. But lately, it escalated to him placing his legs over Deku's and leaning on the other boy's shoulder.
"Kacchan, tell me, have you completely gone gay for me?"
One day, Deku found the courage to 'joke' around.
Just like any other day, Kacchan had his arm wrapped around Deku's shoulder as they leaned on the sofa in their room. And it was normal, it's normal for guys to do things like that. If only Kacchan wasn't burying his face in the curve of Deku's neck like a clingy cat, it would be.
On a normal occasion, Kacchan gets flustered and throws him off the sofa, swearing curses at him for being too conscious of things that shouldn't be given a different meaning.
But today, Kacchan merely looked at him with his fox-like scarlet eyes. It was clouded with emotion that he was sure he had never seen before, yet it seemed so familiar. Deku knew it would be pretentious of him to assume, yet it felt like he knew what it was.
It was lust.
"Dream on," Katsuki said, burying his face once more on Deku's side. "Why are your nipples hard…?" He began to pinch the hardened gland that was protruding under Deku's white tank top.
"Why are you playing with them in the first place?!" Deku shrieked. "Kacchan, you pervert!"
That kind of extreme skinship.
Deku couldn't help but curse himself for not remembering the trigger for Kacchan's changed behavior.