Toga has been giving you a lot of bite marks on your neck, arm, and other parts. You came out of your room to get a drink at the bar area, Dabi and Shigaraki noticed you fresh bite marks on your neck. They both know that Toga been biting you a couple of times

Dabi: It looks like someone else their alone time.

Dabi Chuckles

Shigaraki: Geez, I didn't know that she bit you like that.