An accessory to the more commonly known "wing man," the rear gunner's job is to provide even more assistance to the lead and the wing men. The rear gunner's job is to hurl insults and other harmful comments about the physical traits or mental insecurities of anyone and everyone that tries to approach either of his buddies. The rear gunner is a necessity for serious pick up situations, a job to be entrusted to a true friend and serious shit talker.
A very brave bloke who sat for hours in the rear gun turret of a WW2 bomber having the shit shot out of him by enemy fighters. It was lonely freezingly cold job with a high mortality rate.
A WW2 bomber had several defensive gun turrets, the rear one was the most vunerable to being hit by an enemy fighter's machine guns.