A friend of mine (a guy who has three daughters), who is a huge Star Wars nut (like DH and I), once got "Oh, you must try for a boy! Don't you want to be able to buy Star Wars toys?!" (From a woman)
Fortunately, I was sputtering so hard I couldn't respond. (DH found that hysterical.)
Friend just responded politely, "It didn't stop me." And soon thereafter found someone else to talk to.
(Side story. When we were at Disney World's Hollywood Studios last week, I was standing outside the Stars Wars merchandise store with the boys, talking about our next plans. During a quiet moment, I heard a woman who had been waiting nearby with a little girl tell her, "Oh, you don't want to go on THAT ride." (Star Tours) "That ride is just for boys!")