I did a public service. I emailed him:

I have put in a filter on your email address in my GMAIL and have blocked you in my OkCupid application. This is because I did not like the question about my dress size. I found the question rude and impolite. What would have been the next question, by logical extension - "what is your cup size?"?

I am writing to you about it to give you feedback in order to make you more successful with your next prospect.

I am new to the dating scene and I was unsure as to whether my reaction to your question was justified. So I posted an inquiry on a online message board where I have friends who are more experienced and mature. They unanimously voted to block you. So I am not alone feeling that the question about the dress size is inappropriate.

Cheers,
H-B