testie pop means: A teenage boy might say something that is typical of pubity, but it can be very funny to others. This is where a teenage male says “usual” in one word. Then, his voice becomes louder in the next sentence. Other people will shout at him and embarrass him by shouting “TESTIE POOP”. Or, he will cover it up and say “TESTIE POOP” to himself so that he doesn’t feel embarrassed about others not noticing what just happened. (in Community Dictionary, added by Sandra Fernández)