WIZ AND USHER DUET I WANT HER BACK Bye Felicia!

Wiz Khalifa and Usher are doing a brand new song that gets unveiled tonight ... but one raps about the love of his life, while the other sings "good riddance" to his baby mama.  

Wiz and Usher collaborated on a remix of Rico Love's "Somebody Else."  

Wiz seems to be saying Amber Rose left a hole in his heart and he can't fill it.  

Usher starts by wishing Tameka Foster finds someone ... ANYONE, so she'll get off his back.

Check it Out.