Same answer. Bob's decided to take something told in confidence and risk my reputation sharing it. He's not only a bad friend but clearly a risk so the best move is to burn him back and as hard as possible. He's getting dragged in and if he argues Im going to turn it into a larger issue for him. If we're coworkers I'm going straight to HR and asking what to do because a fellow employee infected me and then tried to put the blame on me. Anything but total calculated aggression will justify Bobs behaviors.

I guess it depends on whether you think someone has a right to a reputation independently of how they behave. Thanks for your answer, it was very enlightening.

To clarify, I'm aware there's a difference in perspective occurring. You're approaching it more from if it's beneficial to the larger group. But Bob is supposed to be my friend, if I can't trust him to keep something socially volatile like that a secret then he's failed me at an individual in a potentially harmful way. At an individual level it makes far more sense to bury Bob than say 'thanks for screwing me Bob'

Is your name Alice? I'm pretty sure I posed the question in the third person.