"Have you got a boyfriend?"
That is the one question that I would rather nobody asked me. It usually is the question that gets asked by those family friends or relatives (often female) that you haven't seen for a long time and are often extremely nosey. If you say "yes", then they will be wanting to know the ins and outs of the relationship, etc. Meanwhile, if you say "no" (which happens to often be the case with me), you feel extremely awkward and embarrassed for admitting it. As well as the feeling that the people who asked you that question are going to be talking about you behind your back, discussing their own theories as to why you are single.
The only time I would want to be asked that question is if somebody was interested in being my boyfriend, which is about as likely as me winning the lottery.