Law abidance, Sobriety, and a Good night's sleep. A phrase used to describe a relatively tame night out, vacation, or other experience. However, most often used ironically to describe an unusually eventful time when none of these activities occurred or surreptitiously to avoid self-incrimination.
Father: "What did you and your friends get up to last night?"
Son: "Just the usual LSG, Pop!"
Father: "That's my boy."
Son: (winks at camera)
Father: "Why are you drunk, ill-rested, and calling from the police station?"
Son: "Major LSG last night, Pop."