I'm surprised how all yelling like "why didn't she just tell this dumbass?!" - guys, c'mon, why didn't even consider that she is shy? Teasing him, showing affection is one thing, especially knowing his cute reaction, but telling directly is like confession, and they not even close to this stage. He is learning his new sides with her help, sights that he didn't know that he has (like that someone can actually give him valentine chocolate), and she is falling deeper with him, learning his expressions and knowing that it's all for herself and herself only. She doesnt want him to be eager if he will open up to fast and could slip away, they are teenagers, c'mon, and this is their pure first love. Be patient.
Anyway - I love this so much, as always, this is just some pure sugar shit, I want put it directly in my veins to melt my old stone cold lonely heart.