ollie...similar to the time I worked for a chemist and a guy shuffled up to the counter to ask for a box of condoms (we kept them under the counter...yeah it was a while ago)
I looked at his discomfort and smiled sweetly and asked if he took small medium or large
he looked aghast and said "I thought they only came in one size" I shook my head and said no sir they size them these days for comfort...he asked for medium
Well I was under 16 (the legal age I could sell them) so I then had to go and tell my older work mate in a loud clear voice that the gentleman at the counter would like a box of medium sized condoms.
Poor guy was sooo embarrassed...but for me twas a sales ploy...we had it worked out that if the guy was embarrassed he would take the box of 24 no questions asked instead of the box of 3 he first came in for