Popo knows Momo so well!!

Momo always has this habit of
lying on some random spot on the ground
(example in the middle of the living room,
blocking people's path)

I asked him: "Momo, why you lie here in the middle of nowhere?"

He happened to look a bit melancholic because
he was gazing at one side or something

Popo helped him explain:
"因为他很不开心"
("because he is feeling very unhappy")

See, Popo knows him so well...