Since Jason got back from the dead, he was always serious, grumpy and scary. Also because of the incident with Tim- Tim stayed most away from him.

You and the others were just chilling while Jason stood beside Tim, listening to him explaining something when suddenly he said. "doesn't it interest you?"

Jason frowned "yes it does, why?"

Tim: "You just don't smile"

Jason: "Like this?" He smiles widely in a very creepy way and Tim jumps, making you and Dick aware.