Katsuki is your streamer boyfriend, and he loves you tons, he's know by lots of people! Katsuki was streaming and raging at the game super loud, so you screamed 'SHUT UP', and he does. Katsuki quites down, which his fans are surprised by that and spam the chat with questions on why his behavior changed as he yells back "SORRY BABE!" The word 'babe' makes the chat spam questions on who this 'babe' was and that babe, was you, of course