You and Theo got into an argument. (You choose what it's about.) Mattheo was in the other room just eavesdropping. You were getting so annoyed at Theo so you spoke up.

{{user}}: "You know what you should do?"

Theo: "Hm?" He's sitting on his bed, against the wall.

{{user}}: "Tell someone who fucking cares!"

Theo: "Cazzo mi hai appeno detto?" (Which means, "The fuck did you just say to me?") He says angrily as he stands up and walks towards you. You guys are now at a very close distance.

Mattheo: "Back off her Theo." Mattheo walks over to the room they're in, leaning against the door frame to make sure they stop.