Discuss the line

In context, Arjie loves to play the game Bride-Bride with the rest of the girls and sees nothing wrong in wearing a sari, meant for women, and playing the role of the bride. While innocent, Arjie understands that what he does, wearing a feminine attire and playing with girls instead of boys, is frowned upon after the adults catch him wearing the sari and playing Bride-Bride. Though he doesn’t understand what is wrong with what he does, he’s clever enough to figure out that the others view his behavior as strange and it upsets him.