Kick In The Balls Meaning

(idiomatic) a big setback or disappointment

Example: 2008, Thomas W. Young - The Speed of Heat: An Airlift Wing at War in Iraq and Afghanistan
  This was a real kick in the balls to us because Afghanistan was going on, September 11 had just happened, and we were away from our families.
Jan 23 2009, Wokingham Times - Local Rugby Round-Up
  "Losing to Wallingford was a kick in the balls for us so we know we can't take any team lightly", said player/coach and lock Ben Hughes
April 16 2010, Scottish Daily Record - If you laugh at people for having a go on reality shows then you're an idiot, blasts Barry Hyde of The Futureheads
  "It's still a kick in the balls whether you've made the label drop you or they reject you."