They met in a crowded staffroom, he said he wouldn't be around for long.
But it was her move to Zimbabwe that sealed the relationship and inspired their book, Nick Morrison discovers
It wasn't the most prom-ising gambit. It wasn't even up there with "Do you come here often?" or "What's a nice girl like you doing in a place like this?" But Shirley Tulloch remembers vividly her future husband's opening line the first time they met.
"He said, 'I'm not going to be here for very long'," she says. "It was a bit odd, but I was intrigued." It was only when they went for lunch that day that the meaning of Jonathan's opening remarks became clear.
"He explained he had this ambition to be a writer. One of his plays was on locally, so he didn't think he would be teaching long," says Shirley.
That was September 1993. It was their first day at St Thomas More school in Blaydon, Tyneside. Shirley was the new religious studies teacher, Jonathan the English and drama recruit. Four years later they were married.
As it happens, Jonathan ended up staying at the school for three years, but then it wasn't exactly a classroom romance.
"We were inseparable from the first time that we saw each other," says Jonathan. "There was quite good camaraderie in the staffroom and we would go out for lunch, and we got on immediately but we weren't going out then.
"Shirley used to do a lot of extra-curricular stuff and I used to tag along, so the kids might have had an inkling - children are more intuitive - but nobody ever said anything."
"We shared a lot of interests and we enjoyed each other's company, but we were friends for years before it became romantic," says Shirley. "I don't think there was a lot of gossip - it wasn't a gossipy place - but in any case, we were both single and it was very open and above board."
Shirley had spent two years teaching in Zimbabwe before arriving at St Thomas More, and it was only when she decided to return to teach in southern Africa that their relationship changed.
"It was when I was making those life-changing decisions that I thought there was more to this than just a friendship," Shirley says. Jonathan adds: "I couldn't let her go, I was full of longing. So I followed her, even though I had a phobia of snakes. It was quite a leisurely courtship."
The couple married after spending a year in South Africa, and on their return to the UK Jonathan devoted himself to writing. His novel The Season Ticket was published in 2000, won the Betty Trask prize for a first novel and was later turned into the film Purely Belter. His third novel, The Lottery, won the J. B. Priestley Award in 2004. But Shirley still beat him into print, with a picture book for children in 2000.
This month sees the publication of their joint novel, I Am a Cloud, I Can Blow Anywhere, inspired by Shirley's experiences in Zimbabwe. The novel tells of a 12-year-old girl and her struggle to save her family, and draws on Shirley's experience of Coffin Friday, the day when Zimbabweans gather on the border with South Africa to receive the bodies of relatives who went south in search of a better life.
"When I was back in England, I had a phone call from a lady I knew in Zimbabwe who had to go to the border because her son had died in a traffic accident," she says.
"She said she had to go on the third Friday, and I was puzzled by this, then she said that that was Coffin Friday. She started to cry and I felt so helpless, I was so far away.
"It was the image of bodies being passed across that pushed me to start writing. A lot of this stuff had been with me for a while, it just takes time to process. One day I went up to the computer room while Jonathan was at the cinema and started to write.
"Most of the incidents are based on fact and I wanted Jonathan to do something with the first draft, and it took off from there. He worked on it separately, then passed it back to me. The process took a lot longer with two people writing it."
Jonathan adds: "We felt it was a book that had to be written, but it was something neither of us could have done on our own. Writers are notoriously egotistical, but on this it didn't matter if our names were on it or not.
"Shirley is an excellent plotter, and then I would come in and embroider around it a little bit."
A joint novel between husband and wife might seem to be a risky undertaking, but Shirley says they have avoided the worst pitfalls.
"We had more arguments over Jonathan's other novels, when I was solely the editor and like a teacher with a red pen," she says. "He is an excellent writer, and if you're gifted and someone criticises you then it can be hard. But this was a joint thing, and it didn't cause arguments."
"When Shirley was a teacher, she used to really build the students up. With my books there is no affirmation, just red ink," says Jonathan. "But she knows what she's talking about. When we first met, we wrote the Christmas play together. I thought I was the writer, but years later it is her bits that you remember."
They now live near Thirsk in North Yorkshire with their seven-year-old son and both write full-time. Although they visit schools regularly to talk to children about writing, a return to teaching is some way off.
"I love the children in schools, but not the system," says Shirley. "When I was teaching, I was accountable to about eight different people, and I was sick of being observed so someone could tick a lot of boxes."
"I would like to teach again, but probably not in this country," says Jonathan. "I could see myself going back as long as there were no bureaucracy and meetings.
"I used to find the staff a good laugh and I miss that. The best place to be was the smoking room. We shared it with the cleaners and we all mixed quite happily, and that was fun.
"You get so close to people's lives as a teacher, and that is an absolute gift for a writer."
I Am a Cloud, I Can Blow Anywhere by Jonathan and Shirley Tulloch is published by Egmont Books