What HipHop/R&B song is this?

[Quad]

I'm pretty sure it's called "Gentlemen" but i'm not sure who it's by

the lyrics go something like this:

mistook you for a real good man
let u take my heart into your hands
and i thought you were my friend
but i guess that iw as wrong
shoulda known it all along

thanks in advance!

 

[Quad]

buuuuump