How We Met: Nathaniel Parker & Sadie Jones - 'Seeing his Henry VIII made me fear that I might fall out with him'

Parker says of Jones: 'She channels characters at the drop of a hat, which makes her one of the best people to be on your team at charades: her Dietrich is second to none' (Jean Goldsmith)

Sadie Jones, 46

A novelist, Jones's acclaimed debut 'The Outcast' won the 2008 Costa First Novel Award. She has since written a further three books: 'Small Wars', 'The Uninvited Guests' and her latest, 'Fallout', published earlier this month. She lives in London with her husband, the architect Tim Boyd, and their two children

I grew up around the sort of actors [Jones is the daughter of a writer and actress] where being polite, sensible and acting like an adult was not a priority, which are all sentiments I share with Nathaniel. We have children the same age, and we were introduced by some close mutual friends at a party they were hosting 12 years ago. We got to know one another over long Sunday lunches and children's parties and we felt close immediately: we instantly had fun.

I think that was summed up early on during a lunch at our friends' house in the country, when Nathaniel spontaneously leapt up on to the island unit in their kitchen and started dancing; he does great comedy dancing, with this 1970s groove and it was the highlight of a wonderful, ridiculous weekend.

I love people who are prepared to be silly and honest and tell stuff about themselves, instead of asking things like, "What school do your children go to?" or, "Do you go to Italy?" Life is a serious and anxious business and having friends like that is important – friends who you can have fun with, and trust when you're going through more difficult things.

It was interesting seeing him work on stage: initially all I'd known of him as an actor was seeing him in The Inspector Lynley Mysteries; moving to the stage is a scary thing to do for a screen actor, and I was anxious for him. But he's incredible and to see someone become sinister and genuinely frightening – to transform without putting on a voice – is amazing. Seeing his Henry VIII [in a stage adaptation of Hilary Mantel's Wolf Hall and Bring Up the Bodies, in Stratford] made me fear at first that I might fall out with him. I thought, OK there's the entertaining side of him, but now I can see that there's a darkness there, too.

We've been to a number of red-carpet events together – though, as an actor, he gets more recognition than I do. I remember going to the Galaxy Book Awards with him, going down the endless red carpet in this nice frock, with the crowds going, "Nathaniel, Nathaniel" and asking for his autograph. No one was saying, "Sadie, Sadie." But while he was signing things, he was saying to them, "This is a book awards, that's Sadie, she's an author and she's up for an award [for Small Wars]," and then these reluctant voice started saying, "Sadie, Sadie, please can we get an autograph…" like I was a charity case!

I believe that having a really good friend makes you feel fascinating, and Nathaniel gives me the illusion that I'm never dull, and I think that's tremendously generous.

Nathaniel Parker, 51

After training at Lamda, Parker became a member of the Royal Shakespeare Company, before establishing himself as a television actor, best known for his role as Detective Inspector Lynley in the long-running BBC1 series. He lives in London with his wife, the actress Anna Patrick, and their two children

We met at a children's tea party in north-west London in 2002, when our kids were about five and six. Sadie was with her husband and I was with my wife. They were this dynamic sweet couple, easy to get on with, and from then on our relationship got sillier and sillier.

She became like a sister – we'd annoy each other and wouldn't hold back saying what we thought. I started talking to her about characters I was working on and she'd pitch in with an opinion – which meant I'd have to re-evaluate what I was thinking; as a proper wordsmith herself, she understands scripts. I remember showing her one for a Lynley episode and saying to her, "Good god, this is rubbish, why are they pushing it on us?" And she replied, "It's very good, you just haven't thought about it" – she can be quite fierce – "it could open up this area for you." She's always prepared to challenge you in that way.

I've read some of her screenplays; I thought one particular romantic comedy was fantastic, and I can't understand why people haven't taken it up. As a novelist, she has this Noël Coward [pathos] and her books are so alive and stylised; even the way she describes walls makes them come to life. Before Small Wars came out, Sadie had the idea of the four of us reading chapters of it out loud in our lounge, over a few days. It's exciting reading a book aloud with the author, and it felt so boho-chic!

My wife doesn't like going out to awards and event parties, while I'd go to the opening of an envelope, and I usually get a plus-one, so I ask Sadie. It's funny when [showbusiness] friends see us out regularly, though, and they never see my wife; they must think something is going on! In fact, she often gets mistaken for my wife: several times when I've been out with Sadie, the next day we're quoted as Mr & Mrs Parker, while I've even been labelled as Tim.

Sadie believes everybody can access any character in their head – nun or psychopath – and I totally agree. I always wanted to portray a Nazi, just to see what it was in the human psyche that could flick that switch from humanity to evil [Parker played Albert Speer in the 2006 BBC 2 documentary Nuremberg: Nazis on Trial]. And I think Sadie can channel characters at the drop of a hat, which not only makes her a great novelist, but one of the best people to be on your team at charades: her Marlene Dietrich is second to none.

Nathaniel Parker will be appearing in the RSC's productions of 'Wolf Hall' and 'Bring Up the Bodies' at the Aldwych Theatre, London WC2 (aldwychtheatre.com), to 6 September. 'Fallout' (£14.99, Chatto & Windus) is out now