So I’ve been giving this a lot of thought and, even though we all know that Yousef leaving was something super unnecessary, I’ve realized something (maybe someone has already come to the same conclusion and shared it but here it goes): the fact that after their date he still left (and it wasn’t presented as something super angsty, since Yousef said “but I’ll be back” with a smile on his face) is showing how much they trust each other, and how strong their feelings are.
They know that a summer apart is not going to make their feelings go away, no matter how much or how little texting they do. They know that when Yousef is back they’re gonna look at each other with huge smiles and it’s gonna be beautiful and they’re gonna talk for hours on end because they will want to tell each other everything they’ve done even if they already kinda did by texts. And by texting during the summer they’re gonna get to know each other more and they’re gonna grow more comfortable around each other (maybe Yousef will stop feeling so shy that he needs to throw grass at Sana). If anything, their feelings will grow and after a little while they will officially become a couple and it will be beautiful.