1.
During the Viet Nam war, US pilots were getting shot down because of surface to air missile SAM sites. In an effort to counter-act the losses, the USAF came up with a tactic called the hunter-killer team concept. This tactic required a pilot, the hunter, to fly low over an area of suspected SAM sites in order for the sites to start shooting. Once the SAMs started shooting, pilots in follow-on aircraft, the killers, dropped bombs and fired missiles to disable the SAM site. When told of the new tactic at a pre-brief, one pilot was reported to respond, "You've gotta be shittin' me!" The term is associated with Wild Weasel pilots who flew F-105s, F-4Gs, and currently F-16s.
Currently, the term is used as an exclamation of shock or disbelief.
"Hey, dude, I heard there was another hurricane headed towards NoLo"
"YGBSM!"
See usaf, wild weasel, pilots, tactics
2.
you gotta be shittin me
boss---you need to (insert the impossible here)
employee---ygbsm
See old school, sex, fart, stinkhole
