IMO, I believe Stiles and Derek realised their feelings in season 3/4. For Derek in season 3, he had a doubt before that but I feel like it was confirmed in season 3 , in a way that I can't escape this.
Exhibit A:
When Stiles was the Nogitsune, and Derek looked tired af:
Derek believing Stiles over Jennifer
Derek running behind Stiles making bad decisions
Would you feel any remorse, Putting Stiles down?(Derek's breath hitching and him looking worried?)
Them comforting each other :
Stiles being confirmed as Derek's anchor, Hello?
Stiles debating whether to leave Derek alone and the look in his eyes
Derek's soft "Hey ,Hey, Save him" To stiles
Stiles saving Derek in the elevator AGAIN
This little look, showing that THEY obviously have an understanding between them, which NO one else sees
Pt.2 of a little look, showing that THEY obviously have an understanding between them, which NO one else sees
PT.3
Bonus for Stiles (Like what was the reason ??)
Anyways I am on a writing spree and feel like writing a fic on this
