Dearest 100 Hour Board,
Part of the chorus from "Trouble" by Iggy Azalea (with Jennifer Hudson) says:
And the way that you kiss your teeth
Excuuuse me, by how can someone kiss their own teeth?
Dear Super Scarlet Demi God Mystery,
It's just an expression, you silly. The way I've usually heard it is "suck" one's teeth. Here are too many videos on YouTube where people demonstrate kissing/sucking their teeth! It is precisely used to convey things like annoyance and disbelief. Urban Dictionary, back me up! It is very similar in meaning to "clucking" at someone with your tongue after they say something regrettable.
In case you were wondering what the onomatopoetic version of this sound is, no one knows for sure, but some clever folks on Yahoo! Answers have given a few suggestions: "mfsuuuuuuuup", and "chluuuuuurp". I don't know about those. I'd probably go with something more like... "mfiiib." My cat agrees, as he immediately came over here when I started practicing the sound.