Jealous

Derick watched as Lennon spoke words of comfort to Liam, hiding his pain. He always considered Liam highly even when others get annoyed with him. And he knew how to talk to Liam without annoying him.

Derick found it funny how he suddenly feels different about Lennon. He's known him for ages and he never liked him. Even Rory could not convince him. But once he saw his vulnerable side, just at a moment's notice, his heart changed.

He's not too bad!

Liam walked away. Derick leaned on the wall and Lennon joined him. Lennon was following Liam with his eyes and Derick did the same.

Then he saw it. The very short but well-communicated interaction between Liam and Rory.

Liam looked down. He appeared to be tired and just wanted time alone. But he did not leave his room yet. He looked for Rory. She was standing with her back to him. 

Derick thought he would call her or walk to her and tell her that he will be in his room.