The Gentleman's Six Pack is the classiest of all evenings a man can enjoy. By definition, it is 7 beers, one more than a six pack. In real world application, it is having one more beer than a man should have had on any given evening.
A: "Dude, you alright?"
B: "Sure man, I just had a gentleman's six pack."
A: "Let's get you some tang, brah."