Cute little sky (obviously a pet name)

From the Sierra Morena comes a pair of little black eyes --
Cielito lindo, carrying a grudge (it says "of contraband" literally, but this is idiomatic)

REFRAIN : Ay, Ay, Ay, Ay, Sing and don´t cry, Cielito Lindo, because singing warms the heart

If the bird that abandons its first nest finds it occupied upon returning,
Cielito lindo, then it´s getting what it deserves.

And that little mole you have next to your mouth --
don´t give it to anyone close to me (Don´t kiss my friends, I believe is what he´s saying)

REFRAIN

Of course, the song can be translated many, many, ways, but as with any poetry or music, you can never recapture the beauty of the original language. Anyway, the song is about a girl who dumped this dude and now she wants him back, but he´s taken and he´s happy with his life. He tells her to quit crying and just sing, cause singing will make her happy. I think he´s trying to be a bit facetious, kinda like saying "I´m happy now after you broke my heart, now what´s your problem?" or "now you see how it feels". Whatever the case, the singer is obviously having fun with this. This is perhaps one of the best-known folk songs from Jalisco, or from Mexico in general. It´s an awesome little song, perfect for drunken sing-alongs, or just having fun.