Dear Doctor. (An open letter.)

So there's a big anniversary coming up, and there are a few things that I want to get off my chest. I don't mention you much in my online life these days – I even sometimes delete stuff from other people that mentions you if they post it on my page. Sorry about that. I suppose I worry about being perceived as a 'fan', and all the preconceptions and assumptions that come with that, especially by those people I've got to know who work with you in a professional capacity – which is ridiculous isn't it? One of the many things that you've taught me over the years is to not worry about what other people think, so why should I feel the need to play down my relationship with the one man with whom I've spent more time than any other over the past 25 years?

There are those who might suggest that it's because you don't exist - that for a 34 year old adult to have a genuine emotional relationship with a fictional character is something that he should quite rightly be hiding out of shame – but you and I know that's not true, not really. As the personification of the creative expression of the very best of humanity, as the result of the combined imaginative outpouring of hundreds upon hundreds of writers and actors and artists, as the avatar for a group belief in an inherent 'goodness', you absolutely exist. (Which sounds like it's verging on religion, and perhaps you do help fill the god-shaped hole left in my life by my staunch atheism. If that's the case, you do it terribly well – most faiths only have one book of their hero's exploits – I've got hundreds and hundreds of yours!)

The thing is, my coyness about our affair is probably completely futile. I'm sure that anyone who knows me reasonably well is only too aware of how important you are to me. How could I possibly hide a relationship of such intensity? Of course, there have been other men over the years, and oh so many lovers, but I've not yet settled down with a long-term companion of my own. To outside observers it may look as though I've lived alone for the past decade, but I haven't, I've been with you. And we haven't been at home – we've been all over time and space together. I really must try to stop being disappointed by men who don't have two hearts…

Now, if we'd just stayed at home playing make-believe this could all be terribly unhealthy. But we didn't – you encouraged me to walk in the world and try to make a difference. And while I'm no hero, I tried. And am still trying. It's thanks to you that I got involved in campaigning, and activism, and get to work with people like Peter Tatchell. (Whom, by the way, I think is the closest I've ever found to a real world version of you – a true hero who inspires by tirelessly trying to do the right thing. He doesn't have quite your sense of humour though – I was once interviewing him in a cupboard and he took entirely seriously my light-hearted suggestion that he could auction off his semen for charity. And he has a bicycle instead of a Tardis.)

It's thanks to you that my childish fascination with all things 'supernatural' gave way to a thirst for real scientific knowledge. It's down to you, via Douglas Adams' infinite probability drive, that I became aware of Professor Richard Dawkins, another hero who fights for truth in his own way, regardless of how others perceive him. (I met him once, and got him to sign the DVD on which he pops up in one of your adventures. When he asked where he should sign it I told him to scrawl over David Tennant's face. He sighed and asked, "Which one's David Tennant?" Which is odd, you'd think he'd know all your faces – you were married to his wife once, weren't you?)

So I guess my point, if I have one, is just to say thank you for always being there and nudging me in the right direction. When I was younger, making the difficult transition from boy to man, I wandered into a world of debauchery that very nearly consumed me. (I'm SO sorry about that time Tarquin and I took LSD and got you to sign a panty-liner, while you were pretending to be the actor Tom Baker launching his autobiography. You played it completely cool though, didn't bat an eyelid.

It's funny, years later my good friends Rory and Diana bumped into you in a supermarket, when you were Paul McGann, and the shopping list that they got you to sign for me included an entry for feminine products, so there's a sort of symmetry there…) But even at my most deranged, when life was precariously balanced upon a never-ending cocktail of drugs and recklessness, you were there, whispering in my ear, guiding me back from such risky adventure and making sure that I returned with my life when there were friends who didn't. Things got bad, but without you, they could have been so much worse.

Right through my life you've been there. When I've needed solace or comfort you were always ready to take me away in your big blue box. And although there are those who would claim that your adventures are really for children, it's as an adult that I've appreciated your company the most. And we're closer than ever these days, now that I write about you for a national newspaper. It's funny, I go to these big press launches in your honour, and PR people think that they need to bribe us journalists with wine and canapés - just to write nice things about our friend the Doctor! (Oh, and thanks for helping out with my equal marriage campaign, while you were pretending to be the actor Matt Smith.

When you said that it was a cause that you really cared strongly about and I looked you in the eye and said "I thought you would", I just meant that you are caring and compassionate, not that you're a closet gay, which is how it sounded.) And remember those several hours that we recently spent sharing a couple of pints in a theatre bar, while you were pretending to be Sylvester McCoy? (I played along and didn't address you as 'Doctor' even once!) You told me in no uncertain terms to give up smoking – always looking after me, even now. (It was better than the first time I met you in that body, when my parents took me to the stage door of the Cambridge Arts Theatre - I was 11 and so overawed that I forgot my own name… sorry about that.)

You can point to almost any part of my life, and there you are, guiding, coaxing, and inspiring. So I'm sorry that I sometimes try and hide our mutual affection, and I'm grateful for all the support over the years. I know that I've got many more adventures to come, of both the real and imaginary types, and I look forward to sharing them all with you. It's your 50th anniversary later this month, but it's also the 25th anniversary of when we first met and fell in love.

I'll be thinking of you.

Riccy x