KEY POINTS:
Peter Davis says the letter he wrote to the Herald, giving the paper a serve on its line on the Electoral Finance Bill, was "completely out of character". You could say that.
By out of character, though, he doesn't mean that he had a rush of blood to the head, banged it out and sent it off. He is rather more - although also somewhat surprisingly less - considered than that.
He thought about writing the letter for a week before doing it, but now he seems to have a taste for it and has also written to the Listener.
He says, and I believe him, though many don't, that his wife didn't know anything about his letter until she saw it in the paper on Saturday.
She didn't say anything to him until "somebody else mentioned it to her and she said, 'Oh, so and so said you wrote a good letter'. And she said, 'Yeah, I happen to agree with it myself.' Ha ha."
Funnily enough, I say, and he laughs again and says, "Well, no. She doesn't always".
He has strong views which we hardly ever hear about because "I try to keep out of the political process. I don't step in if I can help it." When he did, "for whatever reason it got politicised and perhaps people thought Helen had written the letter or something like that".
You would think this would annoy the hell out of him. If he ever has been irritated by these sorts of things - and they are the least of it, really - he got over it a long time ago.
I felt a bit of a sod when I realised quite a few of my questions were about his wife, but I shouldn't have worried.
But perhaps that's why I hadn't written "Peter Davis, husband of" on the memo to the photographers. I just put his name, which is a plain sort of name, and that we were going to see him at the university, where he is a heavy hitter in the field of public health research.
"So, who is this geezer?" said the photographer on the way.
"He's the Prime Minister's husband," I said. "Really? Is he?" said the photographer. "Cool." Then he said something rude, the gist of which translated as: "Why the hell would he want to talk to you?"
The truth is, I don't know why and I still don't, really, but I suspect that at least part of the reason was so he could give me a few tips on how to do my job better.
He thinks I muck around too much, scene-setting and so on, and writing what I think of people and that I should cut straight to the chase, the chase in this case being him.
I ask, gingerly, although I need not have bothered, about a report in the Pacific Journalism Review that read, "Clark's partner is often characterised as a lap-dog carrying Clark's handbag and sheepishly following her and obeying her, and as being completely overshadowed by her".
"Aah, when she goes up to speak she says: 'Can you [take the bag]?' so I do grab it!"
This is practical, but the perception is offensive, surely?
"I can understand it. Helen's a strong woman and people wonder, you know, 'How does that guy manage?"'
Pretty well, I'd say. I did ask, because I knew everyone would assume it, whether he'd told the PM he was going to talk to me. Actually, I said, "I hope you told Helen", because I didn't want her coming after me (I told Davis his wife just about gave me a heart attack once sneaking up on me at the airport and he said, "I'm sure she didn't mean to. She wouldn't like to scare people." Hmm.)
He did tell her about this interview "and she said, 'Oh, that's fine'. Not that I'd ask her permission but sometimes there might be the odd occasion [where she'd say] 'Are you sure you really want to do that?"'
But why does he do interviews at all?
The PM once told me that he did them under sufferance. But he says no, he's "quite happy to do those things. It's just that they make me nervous because the media can be so capricious ... because your reputation and everything can be just smeared in a trice and you've got no comeback so that's the only reason, cos I've got nothing to hide". When I say, "that private investigator who was supposed to be following you would have had a dull time of it, wouldn't he?" he agrees with alacrity. "A very dull time."
I didn't raise the Investigate story, he did, but I did raise the Holmes interview with that prurient question because I have long wanted to know why he didn't just say, "Mind your own bloody business".
"I'm too polite, basically," he says. He did find the question "a bit upsetting, really. I thought it was taking a liberty and I wouldn't ask him that myself, frankly. Ha, ha, ha".
I wondered whether he thought it mattered what the perception of him was and he said, "I think it does because the public, of course, are not sitting down and thinking about politics most of the time, they're getting on with their lives. So what influences them are little snippets and insights and perceptions.
"And so if they think she's a control freak or she's got a loveless marriage, if they get those impressions then it would influence them in a way which I think would be unfair. But at the same time I don't like putting on a show."
He remembers, cringing, the time he was instructed by a photographer to "oh, give her a kiss. And they played it as though we were having some semi-pornographic session".
Being against public displays of affection, I do not want to think about this, but he thinks we could have "a bit more in New Zealand life. I think we could be a bit more expressive, frankly ... I think people should, if you feel something is worth showing good feeling about, like giving somebody a hug, I think you should bloody well do it".
He loves sport for the emotional display, "because you see people genuinely absolutely either outraged or pleased or in pain. I think it's one of the few areas where people suddenly are themselves - both the people watching and playing".
Let's not get carried away. He wore a tie to the netball the other night. "Well, I thought I'd maintain standards, ha, ha! And it was from Louis Vuitton." He was given it in Valencia. "I know you wouldn't buy one," I say.
"Look, it's one thing about the job, Helen gets given a heck of a lot of things. Like this mug, you see!" he says, pointing at his Dairy Workers Union mug. "You wouldn't normally go out and buy one."
I say I know he wouldn't because he and Clark have Peter and Helen mugs which look as though they were made in the 70s.
"Do you," I ask, "think your notorious frugality is overstated?"
"Well, our existence is comfortable and, actually, Helen's more frugal. Like the other day I said, 'we need a new fridge; we need a new washing machine'. She said, 'what's wrong with them?' I said, 'that fridge we've had for 20 years and it was second-hand at the time so for God's sake we can afford a new one'. Fortunately it gave up the ghost."
He is "quite a sentimental person" and tells me about how, having recently been in Passchendaele, there "was barely an occasion when I wasn't shedding a tear". Talking about it makes him cry now, which was unexpected, to me, at least.
There is much that is surprising about him, if all you know about him is what you read. One thing I read came from his wife, who said he wasn't good at small talk but he says, "oh, no. I'm very, very good at it".
I bet he is, too. He is very entertaining, sometimes in a slightly dotty way. He certainly amused me with his musings on how netball could be good for young Islamic women who "could play in a rather ladylike fashion, probably. Look at the way it gets kids in. It's a bit like, you know, marching girls".
Me: "Marching girls!"
"You know, it's something for people to get involved with, as a team."
Me: "Marching girls!"
"Yeah, to show off their expertise and all the rest of it. I don't know if there are any left. I just remember that Cath Tizard used to be the patron of the marching girls."
Despite being fabulous at small talk (I'm not being snarky), he doesn't like to go out socially too often. He does interviews for his wife, "because I think she's quite an extraordinarily gifted person and anything I can do ... I don't want to be a deficit". Hardly. If I was the PM I'd order him along on every social occasion - but I'd like to see her try.