When you are in the Shell 1 Core listening to Ocelot and Solidus using the directional microphone, point it to the left of them (just to the right of the flag pole). You will hear the same guard from Metal Gear Solid on the toilet. He makes some funny comments and says what happened to him and how he ended up at the Big Shell.

While walking Emma and covering her with the PSG-1, when she reaches the second tank use your directional microphone. He will halt and let Emma go free then discover that he has allergies on good looking women.