Ok, except what if only the target is within earshot and it's used exclusively to make that person feel like shit? And would this be true of any other insult that could potentially apply to someone else, like being bad at something? Although I guess if harm is the goal, empathy isn't exactly a priority.

I'll concede you're right about collateral damage, though. Friends of mine know I don't actually believe the insult in most cases (especially penis size, what am I, 12?), but I use more tact if I'm worried it would upset present company or being up bad memories, etc (more commonly fat shaming). I also don't insult people like I used to, though.

But, I don't really hold anything sacred and I'm not about to hold back a good insult for a hypothetical person.