Ricky Martin, Megan Fox, Lady Gaga, that Duncan bloke from Blue, isn’t it about time that celebrities coming out as supposedly “bisexual” just admitted they were really gay?

If you find yourself nodding to the sentence above, I’m afraid you’re part of the problem. Bisexuality exists, and it’s curiously disbelieved. Which is strange, when you consider how easy it looks in the dictionary.

We live in an age of ‘out’ actors, politicians and musicians, even a few athletes and sportspeople. It’s not as difficult as it used to be to find gay and lesbian people in the media these days. So why do so many people continue to deny the existence of bisexuals in the press and accuse celebrities of lying?

Across the internet it’s easy to see people saying the same old things every time someone comes out as bisexual: “There’s no such thing, admit you prefer men!” or “He’s just doing this to appeal to the pink pound!”, but I congratulate Duncan James (you know, that bloke from Blue) on having the courage to come out accurately. I don’t know if he Googles himself much these days, but I hope he’s not put off by the bizarre biphobia.

I am a bisexual man, and I use that word because I want to be honest. So if people want me to come out as “gay” then I’d need the word “homosexual” to mean “sexually attracted to both the same sex and the opposite sex”.

Supposing it did and “heterosexual” meant “attracted to both” too? Then all gay men would simply be straight men who hadn’t met the right woman – but surely that sort of argument died out a while ago, didn’t it? No one campaigning against same-sex marriage or waving Bible verses at us at Pride is doing so because they think homosexuality is imaginary. But bisexuality is still regarded as some sort of unicorn, and bisexual men are still lambasted as supposedly being closeted gay men who haven’t given up on their opposite sex attraction. Then again, maybe I just haven’t met the wrong woman…

I don’t say “I am bisexual” because I’m attracted to men, or to women, but because I’m not solely attracted to one gender. It’s as simple as that and it’s not impossible – why should it be? Sure, over time my partners have tended to be one gender over another, but I like both liver and lettuce – and no-one’s insisting I should admit I’m really a vegetarian if I eat less of the former. Purple isn’t really red any more than it’s really blue and calling us liars, at the moment where we’ve gotten the courage to be honest and face the prejudice, is both insulting and patronising.

I have met hundreds of bisexuals and when the question of being out as bi on the gay scene comes up, everyone agrees: being denied a voice is bad enough but being denied our existence is appalling.

If you don’t like Mozart, it doesn’t mean some other people are lying when they say they really do. Some people really like aubergines, some people really enjoyed cross-country running at school – some people really do enjoy the things you don’t. Some people really are bisexual.

The definition is easy, it’s the prejudice that’s hard.

Marcus Morgan is the co-ordinator of The Bisexual Index, a UK bisexual activist group. Read more about them, and bisexuality at www.bisexualindex.org.uk