Boruto had just been caught using a Scientific Ninja Tool in the Chunin exam. Naruto had already taken off Boruto's Shinobi headband which implied Boruto was no longer a ninja of Konoha

Boruto: I-I... he says with tears coming from his eyes as everyone in the stadium watches him in dishonor I did this all for you dad! To make you proud!

Naruto: We will talk about this later, Boruto he says whilst thinking of how to handle this situation further