WARNING: Adult Language In This Post

Amy asks: In the song My Humps by The Black Eyed Peas the line goes like this "I mix your milk wit my cocoa puff, Milky, milky cocoa, Mix your milk with my cocoa puff, milky, milky riiiiiiight." What the heck are they singing about?

Believe it or not, there are actually web sites that do nothing but translate slang. I found a good translation of this song here:
http://www.slangcity.com/songs/my_humps.htm

Here's the phrase you're asking about:
I met a girl down at the disco
She said hey-hey-hey, yeah let's go
I can be ya baby, you could be my honey
Let's spend time not money
And mix your milk with my cocoa puff
milky milky cocoa
mix your milk with my cocoa puff
Milky milky
Right

Here is their translation:
I met a girl down at the disco
She said hey-hey-hey, yes let's go
I can be your girlfriend, you could be my boyfriend
Let's spend time not money
And have sex
Right

There is also a note about the bottom about the term "cocoa puff":
Cocoa Puffs are a sweet chocolate breakfast cereal for children. However, as in Trick Daddy's Sugar, Gimme Some and other songs, such as Petey Pablo's Fool for Love (my baby got some good stuff/I'm coo-coo for cocoa puffs/time to break out the candles/and old Marvin Gaye) it has a sexual meaning. In the other songs, the cocoa puffs represent black women's breasts, but here, the woman has milk and will.i.am is the cocoa puffs. While milk could be her breasts, it is probably also a reference to skin color. Will.i.am is black and Fergie is white.