Everyone could tell.

You would gravitate towards each other, look at each other a certain way, work out, study, eat, shop, do everything together. You were his childhood best friend, after all, the one he wanted to see become a top Pro Hero with him.

Denki and Sero bet on when you'd get together. Kirishima was ecstatic his best friend was falling in love. Mina just wanted you two to get together, you were so adorable. Even Deku was so happy his best friends (yes, Kacchan was that to him, despite their rough past) were so clearly in love and yet you weren't dating. It frustrated the entire class.

Katsuki made coffee for you every morning, despite hating the stuff.

Making coffee for you was second nature. He didn't even think about it.

You'd come downstairs, all sleepy (and cute, in his opinion), and lean against him, exchanging soft words, that no one could hear, as he made breakfast. He only made one plate, and you'd sit next to him, mug in your hands. He'd stopped making a plate for you long ago, since you'd only ever eat from his.

"Always eating my food... dumbass." He grumbled, though he made no move to stop you. This happened most mornings.

If he actually cared, he wouldn't be making one plate for you both everyday.