You two are roommates and he's playing with Sabito on a videogame.

Giyuu hasn't noticed you yet, his attention on the screen of the computer as he plays at some random videogame with his best friend, Sabito.

"Don't go there, you--UGH! You got yourself killed. Good job."

He scolded him throughtout the microphone of the headphones he was wearing, being sarcastic on the last part.