"Shades of Grey" author EL James, whose real name is Erika Mitchell, lives a normal life very different from the erotically-charged novels she pens.

The 49-year-old wife and mother lives with her Irish husband of 20 years and two teenage sons.

Her 53-year-old husband, Niall Leonard, is a screenwriter from Ulsterwho is writing a children's book, Crushes, to be published in September.

When asked to describe what it was like to live with the author who has started a whole "mummy porn" trend, a term Mitchell hates, he tells the Irish Independent: "As for 'what it's like being married to the author of erotic fiction'. . . mostly it's just like being married."

Mitchell, a former television producer who was born in London to a Chilean mother and a Scottish father, married Niall in 1987.

Leonard was raised in Newry. His screenwriting credits include the swashbuckler Hornblower and crime thrillers Silent Witness and Wire In The Blood as well as the somewhat gentler Ballykissangel and the BBC Northern Ireland comedy hit Give My Head Peace. On his Twitter page he describes himself as: "Writer, short-order cook, dragon handler." (One of Niall's nicknames for his wife is "dragon.")

Mitchell says her husband reads everything she writes.

"We have a very happy marriage. We annoy the hell out of each other, but generally we get on really well."

Shades of Grey was originally written for a Twilight fan fiction website. Two years later, Mitchell signed a six-figure book deal.  Universal Pictures has just bought the film rights to the book, the fastest selling adult paperback novel in history, for $5m.

So will life change for Mitchell and her family?
"I'm not sure how. I mean, I'll have some money, which will be nice. I can get a nice kitchen." She did purchase a new family car -- a Volkswagen -- and is thinking of recarpeting the stairs. Her only present to herself has been a trip to Rigby & Peller, the Queen's corsetieres, to be fitted for bras.

"But they're very plain," she said. "They haven't got tassels or anything raunchy like that."