Why was Hanuman devoted to Rama and Sita?
Sugreevan(master of hanuman) has an evil brother, called VAALI.VAALI can sense anything happening around him, so normal warriors can’t kill VAALI.Hanuman asked Lord RAM to kill him by firing an arrow through the back of VAALI.LORD RAM did so and killed VAALI, resulting in Sugreevan becoming the KING.Hanuman is grateful to LORD RAM from then.