It was the most old-fashioned of courtships. Allison and T, both authors, began by writing letters to each other, sparking a friendship that blossomed into love. The couple met through the pages of the New York Times when they were both invited to write a playlist of their favourite songs. Reading T’s list, Allison felt an instant connection. Little more than a year later they were married. “We seemed meant to be,” Allison says.

Yet there was a less conventional aspect to their love story. T had been born female. When it became clear that Allison was more than a friend, he mentioned it to her, at the same time assuming she’d realised. “I actually thought she knew and wouldn’t be hanging out if she had concerns.”

In reality, Allison had had no inkling but said the only shock was how little the news perturbed her. “I took it in my stride,” she says, attributing her reaction to age and life experience. “I was a fully grown woman, I had two children – I had sampled a lot of life. I’d worked as a journalist for decades and supported myself since I was 17.”

More than that, Allison, 47, says the idea that someone’s gender can alter a person’s feelings – or that a change of gender fundamentally changes someone’s character is wrong.

“I think if you love someone, you love someone, full stop. People evolve and change in ways that can be just as profound [as gender].”

Today, eight years after they met, they are sitting side by side in the home they share with Allison’s two daughters, and it is clear how close the couple are. They swap in-jokes and pull faces when asked to describe what it was that brought them together, discussing the start of their romance in a mocking, but affectionate tone. “How I remember it is … she saw my picture,” teases T, referring to the photo that accompanied his newspaper column.

“Sure,” Allison scoffs, before deadpanning that her initial email, “sounds creepy – it wasn’t”.

Yet Allison admits to “some clutching of pearls in my family, a bit of ‘think of the children’,” when she told them about the relationship. But she had no qualms.

“Once you meet T, you realise how preposterous that is,” she says. “I just knew my children would see this incredible person and our amazing, healthy relationship – and have someone who has turned out to be an amazing father.”

Her only worries, she says, related to building a family life. “We were a very tight unit so my concerns were not about T being transgender or not, or Jewish or not, or short or not, but would he integrate into our family in a way that was healthy and beneficial?”

Allison’s daughters were very young – six and seven – so there was no “big sit down on the couch” to explain the situation. Instead, T, who is 43, and Allison provided them with information suitable for their age, and more as they got older or if situations arose. The children’s complaints about having a new parent, she says, were never about T’s identity. “They took him as he was. It was, ‘T won’t let me stay up and watch TV!’ It wasn’t like every night is about processing gender,” she says, laughing.

Now the only source of anxiety is the small, heartbreaking miscommunications that can throw the family off balance. Although T had been a man for years before he met Allison – he had taken hormones and had surgery during his transition – his parents would sometimes forget and use the pronoun “she” – slips that wound.

“I wish I didn’t care, but it’s hard not to. It’s about a basic right to be seen as you want to be seen and called what you want to be called.”

The fact this happened in front of his children made the situation worse for T: “My primary concern was that the children wouldn’t feel weird or that their life was going to be upended because people were not working very hard to say and do the right thing,” he says carefully.T is at pains to stress that his path to acceptance as a man has been remarkably easy when other trans men and women face stigma and violence. His family have, mostly, accepted his choices, but he agrees that this point of friction over gender pronouns reveals his parents’ underlying anxieties.

“Some of my parents’ issues are about a fear of what could happen for me. And some of it is a bit of heartbreak that [being trans] was hard for me and they didn’t know.”

“As a parent you always think, what am I doing to cause this? Which is a self-centred way of looking at things. Kids are their own people. If you have a child who has felt something was ‘off’ their whole life – ie, they were miserable – and they become who they are meant to be, surely it should be a cause for celebration?”

Another anxiety is the high rates of violence trans people face. According to the US National Center for Transgender Equality, more than a quarter of trans people have been assaulted because of their identity, and trans women and BAME (black, Asian and minority ethnic) trans people face even higher rates. T himself was once threatened at knifepoint.Statistics like this, T admits, are always in the back of his mind. “When we lived in a rural and really conservative, Christian part of the country, I was fearful that [my history] would bring harm or stigma to Allison or the kids,” T says. “In New York, we didn’t even have to think about these things, but you move somewhere like that and you have to worry.

“You don’t want to bring trouble to this person who you love more than anyone in the world.”“You don’t want to bring trouble to this person who you love more than anyone in the world.”

“We have been incredibly lucky. For other people, I have heard it spurs incredible violence.”

They laugh as they remember one particular neighbour who wore camouflage fatigues and once presented T with a freshly shot deer. “That was a little scary. I didn’t want him finding out because, who knows?”

Usually, though, they meet people who see them as exotic because of T’s gender history. Allison recounts how one neighbour was excited after she Googled T – who has written a book about living as a transgender man and his views on masculinity. “She said, ‘Oh, I just love you guys even more!’ as though we were a collectible item. But I’ll take that over nastiness any day.”

Allison and T are optimistic that the growing profile of trans issues is changing perceptions, particularly for younger generations. “Our younger daughter is in a large public school and it seems like things are improving. Girls can shave their heads without being called dykes. When kids use homophobic slurs, other children question them.”

Gender-fluid celebrities, such as Miley Cyrus, also help to break down barriers. Allison, who recently interviewed the pop star, says, “She says some days she wakes up as a 16-year-old boy and so that’s who she is that day. She’s living out those identities. She does a lot of work with LGBT charities.”

Allison and T have written a young adult novel series and are in talks to develop it as a TV series. In it, the protagonist discovers he is part of an ancient race of people who change gender identity every year, finding themselves in a whole new body. In the first book, Drew awakes on his first day at high school to discover he is a girl.

The inspiration was their experience as parents. “We had a particularly ‘pre-teen’ morning with one of the kids,” says T. “They had woken up like a dragon and we started thinking about how kids seem to move out of identities daily, if not hourly.

“We wanted to make it literal – how your exterior reflects how you are perceived and whether you are welcomed or rejected in the world – even if you are the same person inside.”

They are trying to encourage empathy for different people’s experiences, says Allison. “What is the difference between a woman who gets plastic surgery to become the woman she wants to look like and a trans person? Why do we draw these lines? They break down if you think about them.”

The couple have been visiting schools, encouraging children to think about what it would be like to be someone else – their mother, for instance, or brother or friend. And Allison says that while many people may focus on the assumption that a child with a trans parent will be teased or confused, there are as many positive experiences.

“The one thing I have noticed, now that both my daughters are teenagers, is that they are tuned into discrimination on every front. That might have been the case anyway, but the younger one, in particular, if she sees someone being teased on the bus – for their religion, for instance – then she is the first to step in and say ‘That’s not cool.’

“If she hadn’t been raised in a house that was so full of difference she might not be like that. People say, ‘Oh, the children’ – as though you are setting them up for a horrible or challenging life. But my answer is that every child’s life is challenging and the very things that are difficult can make them into better people.”

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