Throughout their marriage, he felt guilty and confused, ashamed that he was, in his words, "ruining one woman's life."

Jang did not hear the word "homosexual" for the first 37 years of his life, saying he had no concept of what it meant, something not unusual in his native North Korea.

"When I was in Pyongyang University, I went to see a neurologist, wondering why I was so different to others," he told CNN.

"But as soon as I started talking about my feelings, I had to run out of the office, because the doctor started yelling at me."

Jang Yeong-jin says he knows of other people in North Korea who have had the same experience.

'I knew I had to leave'

Jang says he could cope with limited food or clothing in North Korea but having nothing to dream for left him miserable.

He says the closest he came to a dream was a childhood friend he later realized he had been in love with. Their innocent childhood closeness spread well into adulthood. Holding hands or sharing a bed was not unusual he says, as both of their wives knew they were close.

"One day my friend came to see me," he says. "That night I left my wife's bed and got into his, my heart was beating so fast as he slept and I couldn't figure out why I felt so hurt by him."

"I got up, went outside and saw a wild goose flying over my head. I knew then I had to leave."

Flight to freedom

Jang fled across the border into China in 1996, where he struggled for 13 months to find a way to South Korea. China regards North Koreans as economic migrants rather than refugees or defectors, if they are caught they are usually sent back to face punishment.

Photos: Unseen in Pyongyang "Like a stage" – London-based amateur photographer Michal Huniewicz recently visited North Korea as a tourist. He snapped dozens of images during his trip -- some permitted, others not. Huniewicz took this photo from the window of a train as he pulled into Pyongyang from Dandong. "It looked like something you would see in a theater," he says. "It's a bit too perfect." Hide Caption 1 of 14 Photos: Unseen in Pyongyang Candid moments – Huniewicz says this is just one of two photos in which he was able to capture a candid smile from local residents. Hide Caption 2 of 14 Photos: Unseen in Pyongyang Pyongyang Metro – North Koreans head down to the Pyongyang Metro. It's 100 meters underground thus riding the escalator down to the station takes a couple of minutes. Hide Caption 3 of 14 Photos: Unseen in Pyongyang Victorious Fatherland Liberation War Museum – "Who's American here?" the museum guide asks. "Grab the flowers, go to the monument, bow, and lay the flowers there." Huniewicz says North Koreans told him they single-handedly defeated the U.S. in the Korean War. Hide Caption 4 of 14 Photos: Unseen in Pyongyang Wish you were here – A woman sells postcards, stamps and posters, many featuring themes focused on defeating the U.S. and destroying the White House. Huniewicz says he did send one such postcard from North Korea to the U.S. and it arrived with no problems. Hide Caption 5 of 14 Photos: Unseen in Pyongyang Speeding past slums? – These settlements, captured from a speeding van, appear to be slums outside of Pyongyang, according to Huniewicz. He speculates that the tourist transport vans slow down when passing what the authorities are proud of showing and speed past less desirable sights. Hide Caption 6 of 14 Photos: Unseen in Pyongyang A helping hand – This may look like an ordinary scene in any country, Huniewicz explains, but in North Korea, he feels it challenges a local song about no mother's love being greater than that of the Communist Party. Hide Caption 7 of 14 Photos: Unseen in Pyongyang The commute – Riding the Pyongyang Metro. The underground network has two lines and 17 stations. Hide Caption 8 of 14 Photos: Unseen in Pyongyang Center of the capital – This scene was captured during a dance held to commemorate the 70th anniversary of Liberation from Japan at Pyongyang's Kim Il-sung Square. Hide Caption 9 of 14 Photos: Unseen in Pyongyang Evening walk – Women in traditional Korean dress head to the dance. Though much of North Korea is without electricity, the portraits of the supreme leaders are illuminated brightly. Hide Caption 10 of 14 Photos: Unseen in Pyongyang "No animals were involved" – The Pyongyang circus, Huniewicz says, is genuinely impressive. Hide Caption 11 of 14 Photos: Unseen in Pyongyang A tourist's perspective – Huniewicz makes it clear that all his pictures show North Korea through his eyes. Hide Caption 12 of 14 Photos: Unseen in Pyongyang Shots with consequences? – Huniewicz doesn't think his pictures capture anything highly controversial. Hide Caption 13 of 14 Photos: Unseen in Pyongyang Everyday life – North Korea's apartments remind Huniewicz of the ones he saw in Eastern Europe, the photographer tells CNN. Hide Caption 14 of 14

He then made the unheard of, and incredibly dangerous decision to re-enter North Korea, travel south and cross the demilitarized zone, or DMZ, a four kilometer, mine-ridden border than only a handful of people have ever made it through.

Jang knew the border well. He woke up next to it every day during his 10 years of compulsory military service, during which he was tasked with decoding South Korea's military communications.

"While I was serving on the border, I wondered what life would be like in South Korea and would I live like a real human being there?" he says.

'I always have hope'

Jang says he knows of others who have had the same experience as him in North Korea and assumes many are still struggling to understand their feelings.

"When I was in the military there was a senior officer who had the same problem as me after he got married," he says.

Jang first learned about homosexuality from a magazine in a doctor's surgery in 1998.

"There was also a man in my hometown who never got married and lived alone all his life."

"North Korea society treats these people as abnormal."

Reading a magazine in a doctor's surgery in 1998, not long after he arrived in South Korea, Jang saw an article about homosexuality. It was like a light had been switched on, suddenly he had an identity.

"That was the first time I knew what homosexuality was and I was really pleased," he says. "I was 37-years-old by that time and thought I would be living alone for my entire life after leaving North Korea since I could not live with a woman."

The only openly gay defector

Not that life has always been easy in Seoul. Duped by a swindler in 2004 who started a relationship with him and then stole his savings, his trust in people was greatly shaken. He has no family here, they're all in the North. He has few friends and being the only out gay defector in the South has made settling in twice as hard.

"Since I am a defector, I am a stranger in this society," he says. "For all defectors it is hard to settle down, but for me the hardships double."

Revelers at a gay pride parade in Seoul, South Korea in June 2016.

Jang however, refuses to give into disappointment, pointing out that at least in the South he is allowed to dream. His current dream is that life begins at 60.

"I am very optimistic, I always have hope that I would be able to live like everybody else, loving each other, traveling around the world someday," he says.

A English translation of Jang's autobiographical novel of his life in the North -- "A Mark of Red Honor" -- is due to be published in 2017.