Military joke

It is a normal drill day at the Marine base in Virginia. The whole regiment is lined up in formation, and the colonel is walking around inspecting people. There are rows of marines stacked behind one another waiting to be inspected. The colonel gets to the first squad leader, stands in front of him and punches him in the stomach the hardest he can. After about a minute, the squad leader catches his breath. The colonel bellows, “DID THAT HURT SOLDIER?” Then the soldier says “NO, SIR.” The colonel shouts, “WHY NOT?” Then the soldier says, “BECAUSE I AM A MARINE!”
The colonel gets up to the second squad leader, stands in front of him, and kicks him in the kneecap. After about a minute when the soldier is finally standing, the colonel hollers, “DID THAT HURT?” The soldier responds, “NO, SIR.” And the colonel says “WHY NOT?” Then the soldier shouts, “BECAUSE I AM A MARINE!” 
The colonel gets up to the third squad leader. He notices that there is an erection between his legs. The colonel takes a stick from the floor, and whacks the erection with it. The man barely makes a sound. The colonel asks him “DID THAT HURT?” And the soldier says “NO, SIR.” Then the colonel shouts, “WHY NOT?” Then the soldier points at the man standing behind him and says, “BECASUE IT WAS HIS.”