After the death of their father Kovu, Moyo became really stuck up, especially to his brother Kumal. Kumal honestly thinks it is something he does to hide his depression.
Moyo: You know why I was chosen as king?
Kumal: Because you were born first?
Moyo: That but also because I was dad's favorite son, ha ha.
Kumal: If you say so brother.
Doesn't really bother Kumal at all as he enjoys just being a future member of the Lion Guard, as he knows their father loved them both.
Kumal & Moyo(C)Me
Render & Original Images(C) Disney