RICHARD La Plante, former rock star and psychiatric counsellor, martial arts expert, screenwriter, actor, novelist and husband of the first lady of screenwriting, Lynda La Plante, has written a thriller, Leopard. It is, according to the blurb, about ‘nature’s perfect killing machine’. But turn the pages of Richard’s own life to discover nature’s most unbelievable living machine – a tale of sex, drugs and a woman who was once paid to talk to him.

Richard, 47, has long blond hair, a tattoo, is dressed in black and sits, legs astride, in rock ‘n’ roll pose. He laughs at himself constantly and is Schwarzeneggerishly forceful.

Before Richard wrote, he was the singer in Revenge, a rock ‘n’ roll band. ‘It ended in a New York bar when I slapped the guitar player’s brother for insulting me and broke his nose,’ he says, in his drawly Pennsylvanian accent. ‘He left by ambulance, I left in handcuffs.’

His first job was as a psychiatric counsellor in a Massachusetts hospital. In 1971, he ran off to live in a tent in the Mexican Senora Desert for six months. ‘I wanted to see what I was all about – but I didn’t arrive at enlightenment. I just did a lot of magic mushrooms and bottles of mescal. Then I’d lie there drunk for two days.’ Does he still do drugs? ‘I don’t think that’s a question I want to answer.’

He went then to San Francisco and joined a ferocious-looking hippy called Russell. ‘I lived in a strict vegetarian commune. I gave away my shoes and didn’t wear any for a year.’ Then they walked barefoot – 3,500 miles in three months – to Boston. ‘I was arrested in Utah for being a vagrant and put into jail.’ He talks characteristically with Kung Fu-style hand movements.

He worked next, aged 24, in a Boston mental institution. ‘People don’t frighten me, however freaky they are,’ he says. ‘That’s valuable in the lock-up ward of a psychiatric hospital, because people are like animals and smell fear.’

He ‘bonded’ with two adolescent male patients. When he went on holiday, they broke out of the institution and into his house. ‘When I came back home, they were living there!’ he laughs. He didn’t report them and they stayed for six weeks. ‘When the hospital found out where they were, I lost my job.’ So he went to Mexico and converted a hot-dog stand and sold artefacts.

In 1975, he was best man at a friend’s wedding in England. He looked so strange that Lynda was bet a fiver to talk to him. ‘I was wearing a blue velvet suit several sizes too big. I’d swapped it with a friend who was 6ft 2in and I’m 5ft 8in.’ So it wasn’t love at first sight? ‘No, she wasn’t my type. I liked them dark and Mexican and she was red and English.’ Then they hit it off and Lynda joined Richard in Mexico, for one of the worst trips of her life. ‘She needed surgery in Mexico City and nobody spoke English. While she was being operated on, I was smuggling motorbikes to make money, ate a burger made of donkey meat and ended up in hospital on an intravenous drip. They asked Lynda where to send my body.’ Their relationship suffered. ‘Lynda hated me; I hated her. I couldn’t wait to get rid of her,’ he says. “Then, when she left, I missed her so bad I didn’t know what to do.’

So Richard went to London – where he imported cowboy boots – and cemented their relationship. ‘We fought every day and night for about a year. We still do regularly.’ What about? ‘My being American and not having any manners or social grace. Nothing’s changed.’

They married in 1977. What is the key to their marital longevity? ‘Separate bank accounts and staying out of each other’s way. But the real secret is our fighting. If we don’t like something, we get it out real quick. People who come to our house are often frightened by our relationship.’

Are they faithful to each other? ‘Well, that’s not just physical, it’s a mental thing as well.’ Can he be faithful without being physically so? ‘Yes, but I don’t want to get into that.’ Is sexual fidelity important to him? ‘I wouldn’t like the idea of Lynda with another man at all.’

Lynda had 10 years of a faltering career as a stand-up comic and bit part actress before turning to writing. Now executives trip over themselves to find a slot for any series she offers and Hollywood pursues her avidly. They rarely read each other’s work. But does he live in her shadow? ‘I’m not sitting there saying, ‘She’s doing this, now what am I doing?’ It’s like a parallel street.’

How successful does Richard feel? ‘I feel unsuccessful – until I meet all those people who’re impressed when they ask, ‘Are you published?” Does he live off Lynda financially? ‘No, I pay my own way,’ he says, with a dead tone. But she earns stacks more money? ‘Oh Christ yes, oh heck. She’s in credit and I’m in debt.’ Would he prefer to be the higher earner? ‘I don’t care. As long as I have my motorbikes and my gym. If you want me to say I feel inadequate, I don’t.’

They don’t have children; sadly Lynda can’t. ‘We went through all the tests and did the f***ing by thermometer. Today, with the technology, we’d have been able to have them.’ Thirteen years ago they tried to adopt. ‘The family reneged. They didn’t want to compound the baby’s mortal sin by getting her adopted by a non-Catholic family. It was sad – we had the room ready for her – but we’d never seen her. We no longer want children. Our lives are pretty active.’ Indeed.