Client asking if I'm gay/straight

So yesterday I had a client blatantly just say to me, "so...are you gay or straight?

I'm very openly bisexual, but I didn't think it seemed appropriate to say so.

So I just said that's my secret and laughed it off.

It didn't bother me, but how would you respond?

I've told a client before, and they've literally asked so many questions! E.g. how can you like both men and women?
What do you prefer?

The list goes on and on, and it makes me and others in the salon feel awkward