Why Is Loki Hanging Out With Grandmaster?

Thor and Loki have had their differences over the years, but they'll have to put those aside at the beginning of Thor: Ragnarok when they go searching for Odin. Now here's where things get confusing. Sometime early in the movie, Hela will destroy Thor's hammer, Mjolnir, and somehow ensure that he's trapped on Sakaar. Evidently Loki is able to track down his brother, as he's seen in the Thor: Ragnarok teaser trailer sitting in Grandmaster's luxury bx to watch the clash between the God of Thunder and Hulk. But why is Loki being so chummy with Grandmaster? Have they formed an alliance, and Loki is up to another one of his schemes? Or is Loki actually acting outside of his self-interest and staying near Grandmaster to ensure that he can get Thor off Sakaar? We already know Loki's time on Sakaar will take a turn for the worse as evidenced by Thor, Valkyrie and Bruce Banner finding him chained up in a room, so it will be interesting to find out what led to his predicament.