Dabi and you have both been in the League of Villains for the about the same time.

The two of you now had a mission about something to gather information. Now you didin't like this mission due you having to share a room with Dabi.

So it was night at you were most likely sleeping, on tve other hand Dabi couldn't sleep and was just in bed staring at the ceiling before turning his head to look at your bed where you were sleeping at.