The Dorothy-Killian Relationship, commonly known as Killothy, is the relationship between Dorothy Dandridge and Killian "Hook" Jones.
They met prior to the first episode, Chapter 1: A New Beginning.
The first time we see Dorothy and Killian interact is in Killian's office when Dorothy storms in demanding to know about his glee club "The Poison Apples." He shrugs off all her questions and continuously flirts with Dorothy until Mary Margaret comes into the office demanding to know more about his motives.
Their relationship is first mentioned when Killian is going to meet with The Poison Apples. As he walks in, he wonders about what has happened to him and how he can't believe that he likes Dorothy in that way. He also compliments her, calling her pretty and wholesome, and stating that she will never love a villian like him. His thoughts are then interrupted by the fight going on between Audrey and Percy.
We then see Dorothy and Killian interacting in this episode in the auditorium when they are annoucing their decision to have The Flawless Fantasies and The Poison Apples participate in a competition. Killian, after calming down the fighting teams and allowing Dorothy to speak, gives her a dopey smile, something she rejects with a roll of her eyes. Later in the scene, after she explains about how the competetion will work, he agrees that it sounds fair. Audrey then counteracts him by saying that he only agrees because he is in love with her, implying that even the student body knows about his crush.
Everything is Killothy and nothing hurts!