A shirtless Bobby is a double vodka tonic with limes and is only drank by the coolest most metal shirtless sexy ripped corner dwellers at the bar.
Bartender: What can I get for ya?
Customer: I'll take a Shirtless Bobby.
Bartender: Sure, one lime or 2?
Person A:: "Dude I got so fucked up on Shirtless Bobbies last night."
Person B:: "oh man, they get ya every time!"