Girl on Barstool: I turned round and there was this huge guy behind me
Girl's Mate: Yeah he's really big
Girl on Barstool: I wonder if he's got a really big knob
Yes, that's me they were talking about. I'm aware that, being six and a half feet tall, people sometimes speculate whether my penis is in proportion to the rest of me. I'd prefer it if they discussed it out of earshot; more generally I would point out that just because you have your back to someone doesn't mean they can't hear you.