To call someone "Testicle breath" is to imply that their mouth and at least half of their scrotum have recently been in close contact.
This phrase was coined back at the end of world war 2 in the Bavarian alps by Baron Peter van den Berg, and Lord Scott O'Halloran whilst on a top secret mission to burgling Hitler's retreat 'the Berghof' and liberating Hitlers sodomized dwarf rabbits. Whilst hiking through the alps Lord O'Halloran became frustrated after having just given Baron van den Berg a lecture on something involving a far away and insignificant football team called 'Carlton' when he noticed that Baron van den Berg had actually fallen asleep as he was walking! "Did you hear me Testicle breath!?" Lord O'Halloran shouted at van den Berg, startling him out of his "Carlton football team" induced coma. As van den berg opened his eyes and turned to face O'halloran he noticed that there were American warplanes almost overhead and that they had in fact released a payload of bombs which were directly heading for our two unlikely heroes. With a shocked look on his face and speechless van den Berg began to run for cover. O'Halloran unwary of his impending doom and now totally frustrated by his failing attempts to "spread the Carlton word" as van den Berg ran away began to yell "TESTICLE BREATH! WHY ARE YOU RUNNING" and as he lost sight of van den Berg, O'Halloran began to angrily scream "TESTICLE BREATH!" "TESTICLE BREATH!!" a number of times. O'Halloran's screams alerted some of Hitlers's neighbours to O'Halloran's presence and as they emerged from their homes to confront him the allied bombs began to explode around them injuring many of them and destroying the Berghof. O'Halloran and van den berg survived the bomb raid although Lord O'halloran's hair was burnt to his scalp and These days he is beleived to wear a rather thick wig as a result of his injuries. Many years after the raid upon being interviewed by the BBC many of the survivors of the bomb raid could only describe the situation in their best broken english as "TESTICLE BREATH..TESTICLE BREATH...BOOM!!!"
person 1. "Carlton football team are the best"
person 2. "No, Carlton are a bunch of hand-bags"
person 1 "Shut-up testicle breath"