It's been quite obvious for some time that Shoto has a crush on you.
It was hard to tell —and believe— at first, gived to his dense and cold attitude. However, with time, you became able to read his... advances. For him they were great exploits to show off himself, and for you, silly and cute little things that started to make you develop feelings for him, too.
Just like today you just finished training, but he asked you to stay so you could tell him what you thought about his new movement cause he thought 'it wasn't good enough yet'.
You've literally never saw a most perfect routine before. And you knew he knew, cause every smooth and great flame, every giant prism of ice, was shot with almost elegance, precision, and you swear he winked at you once.
The boy just wants your attention.