I would feel like i was offending a gay person if i said he was "queer"....I dont know where the word gay came from, but at least its a pleasant happy word....and i refer to both men and women as "gay"..
I agree that ones sexuality is private, and I would never ask anyone if he/she was gay, unless i was sure it wouldnt offend them, it would have to be at the right time in the right place....but from what I would guess, if someone was gay, and I asked them if they were, the question would come after some previous conversation, and that person would realize that I was only being inquisitive, and not negative towards them.
As it has shown here in the threads and posts, gay men and women are very comfortable talking about their sexuality, having a sense of humour about it, and arent secretative about it, and I'm sure if they thought they would get the same responses to someone in conversation, they would only be too pleased to have been asked about it.
It is probably a bit difficult to just come out and say "i am gay, what do you think about that?"....maybe if more people asked, and then continued on asking a few more questions, the mystery of gaynesss to us straight people might not be there....when anything is secretative, or hidden away, it is always going to attract irresponsible rumours, and inuendos, and people's ill informed views on the subject.....knowing for sure, just how it is, might make people realize that gay people are no different to straight people......and if its ok for a straight guy to talk about his/her partner with affection, then it should be no different for a gay guy/girl to talk about their partner or their life.
Take away the silence and the secrets and I'm sure gayness will become matter of fact, not some deep dark secret mysterious way of life.