The other thing that exercised my mind for a little while was how the store assistant should have dealt with me, given that she clearly was used to dealing with transvestite customers and had her patter down, er, pat for such persons.
The answer, as several friends since helped me to find is: exactly the same way as any other sales person deals with a customer: by asking questions, working out how they prefer to be treated and then doing that. In technical speak, its called “qualifying the customer”.
That’s why the girl who blurted out “lady” in dealing with me, then looked mortified and asked if that was OK, got it right – whilst the one who just carried on using “sir” and “gentleman” got it wrong.
When in doubt ask. Politely. And listen to the reply.
It won’t instantly usher in world peace and harmony. But it definitely helps.