"I've always been a Diana fan, but last year I woke up one day and decided to paint her name on my forehead - it just felt right," he says.
John is, as you can tell, quite committed to his idol. As a result, he has spent 48 days sitting in on the inquest examining the Spencer girl's death.
He sounds, actually, like quite a nice bloke. And, compared to some of the other people sitting in the public gallery of Court 73 at the Royal Courts of Justice, he seems to be relatively sane.
"I tend to get on with everyone, although I don't like all the chat from the Diana Circle - they say lots of nasty things about Camilla Parker Bowles, and talk about conspiracies, and play Candle In The Wind a lot."
No surprise there, of course, and it is well established that excessive exposure to Elton John's music can damage anyone's sanity. But what is more interesting is that some of the 'Diana Circle'--unlike Mr. Loughrey, who believes the crash was an accident--seem to not only talk about conspiracies but rather see themselves as caught up in one (or, more likely, several).
Such as one 'very well-spoken lady with immaculate make-up and pretty coral nails, dressed in a plum-coloured tweedy jacket.'
"I'd tell you my name, my dear, but when you've been threatened in the past and people have tried to kill you, it makes you more careful," she says cheerily.
"There are quite a few regulars, but first one has to differentiate which are MI5 and MI6 - they're everywhere.
"That couple who were here earlier, for example. He seemed a genuine man but he has the type of shoes that police wear, if you know what I mean."
It barely seems worth asking if she thinks Diana's death was an accident.
"I think there are a lot of people telling a lot of lies - I used to live with the mistress of a Viscount, in Fulham, so I've got inside knowledge - but dare I say that? Oh well, they want to kill me anyway."
I must admit that I find something endearing about Mr. Loughrey's rather excessive form of fandom. It's harmless enough, entertaining for the rest of us, and he seems to be enjoying himself tremendously.
And, however eccentric, he also maintains a very practical approach to things:
And the huge blue Diana on his forehead - isn't it all a bit of a palaver? "My sister Geraldine paints it on with a little make-up brush.
"If I do it myself in the mirror, it's backwards and hard to get the letters the right way round."
Kind though Geraldine is, she won't get up at 5am for him: "She does it at night, so I have to sleep on my back, which I hate, so it doesn't smudge on the pillow."