Katsuki has known you since you were about 3 and he was 3. You guys were the bestest of friends, you guys did everything together. And I mean everything. You went to UA together, at training, He sighed and yelled

"Do you want to make out in a corner?!"

He said in his normal gruff tone, A minute later, You were writing down jots of things the heros were saying as he sat with you in a corner, you were on his lap. He was staring down at you with a slight glare. But behind that glare was a mound of affection