Sharing the same interests or hobbies with your partner is good, but what if the activity involves risking life and limb?

Just ask courageous couples who develop their relationships based on daredevil pursuits like wingsuit flying -- arguably the most dangerous extreme sport in the world – and enjoying every minute of the adrenalin rush.

"With her also jumping, it's great in a lot of ways. We can share the experience and go on trips together. It's nice," Noah Bahnson, an experienced skydiver from the United States, said of his Italian girlfriend Roberta Mancino, who is also a professional wingsuit flyer.

The sport uses a wingsuit that offers a body surface area with fabric between the legs and arms to enable a significant glide in the air. The flight usually concludes with a parachute opening.

"But there is also a downside to have a girlfriend who also wingsuits," Bahnson said. "When I am jumping, I get nervous. When she jumps it makes me 10 times more nervous. I know she's a very good wingsuiter. But it's someone you care about, so you are way more scared for the person than for yourself. But I wouldn't have changed it. I love it."

During the World Wingsuit League China Grand Prix at Tianmeng Mountain in Hunan province, three couples including Bahnson and Mancino demonstrated their high-flying romance fueled by the passion to fly into the unknown together.

Every time before Mancino took a jump, Bahnson, runner-up of the Grand Prix in 2013, double checked his girlfriend's suits and parachute, making sure every buckle was locked. And every time Bahnson safely landed on the ground, Mancino would offer her boyfriend a kiss.

"By doing the most dangerous thing in the world, love is all about taking care of each other's safety," said Mancino, who is also an international fashion model.

Another couple, Rex and Melissa Pemberton, were also drawn together by a mutual passion for the risk and rush. They have built a marriage on love, trust and the extraordinary acceptance that their life partner could die at any moment.

In September 2007, the Pembertons spent three days at Colorado's Royal Gorge, where they jumped off a 290-meter high span bridge. On the last day, Melissa went first but her chute opened faulty with lines twisted. She then slammed into the rock face and hung 60 meters above the ground with a broken leg.

While she screamed for help, Rex appeared at the bottom and yelled up "Melissa, have I told you I love you?"

"And I was ‘really? Right now? You are going to tell me you love me for the first time?' (under those circumstances). So I said 'I love you too' to him," said the 30-year-old, who also earned a pilot's license soon after turning 18.

Every marriage has its unspoken rules and they are no different for the Pembertons, though the stakes are much higher.

"We probably never say ‘No' to each other's passion in extreme sport. We can share and encourage each other without holding back each other's attempts for bigger challenges," said Rex, who first met Melissa in Australia in 2007.

"We very easily cross over our passions," Melissa said.

"Being together, we are more cautious because we are care for each other so we always keep each other in check."