"Just say what you're going to say!" (4,2,3)
I believe the answer is:
spit it out
(Other definitions for spit it out that I've seen before include "Come on, say it quickly - or expectorate" , "Say it quickly - even expectorate" , "Go on!" , "Tell me forthwith!"" , "Come on, say what's on your mind - expectorate if you wish" .)