that actually very much depends.
1. if I were reading or listening to music, I probably wouldn't say anything to you, because generally I prefer reading/listening to music than talking to people. I am shy and self-conscious in rl hense I probably won't start a conversation with you, someone else has to start it. If i meet you online I can natter away to you like there's no tomorrow, but I can't do that offline. I am a totally different person.
2. if I were to start a conversation with anyone I would not ask personal questions of them until I had chatted to them about other random stuff first, like...the weather, current affairs, the speed of elevator repares etc. I would never start a conversation with 'Hi, how are you? are you gay or straight?' for example.
I kind of think that there's a certain amount of polite conversation one has to go through before one can start asking this sort of stuff simply to give both parties the chance to decide if this person is actually someone you want to interact with.
and honestly, when people start a conversation with something like, 'I've always wanted to know' it's like they aren't talking to you because they're interested in you at all, they just want to know some form of information that you can provide because you happen to be the right type of person.

