I don't know, if a friend asks me I'll just tell them, I'm not ashamed about that sort of stuff, because I know I have a much better chance with that girl than my friends do. Hell, I've on several occasions just told a girl flat out that I like her, but then she doesn't feel the same way so we just end up becoming good friends -.-
And about the whole gay/bi thing, it's not cool to make fun of people just because they aren't straight. There was a time a few months back when I thought I was bi, it's really weird and confusing, and not a cool situation to make fun of. Besides, I have a bi friend too, and she gets pissy about that stuff, so I kinda understood how she felt. But I realized I wasn't bi, but I still retained those feelings of negativaty toward those who make fun of non-straight people.
In short, it's not cool or anything and won't make you more appealing to be around, so why do it?