"It doesn't matter whether you're fat, you're ugly, you've got spew hanging out of your mouth or whatever else, there's some lady here who will want to take care of you," Justin says with a grin.

Nine years ago he moved from Queensland to this hard-up, northeastern region of Thailand, known as Isaan, to be with his first Thai wife, whom he met on a trip to Bangkok.

The pair later separated, but Justin said by then he had fallen for "laid-back" Udon Thani, one of Isaan's main towns, where he opened Western bars and went on to meet his new Thai bride-to-be.

"The ladies here are the most beautiful girls in Thailand, Isaan ladies, and money-wise too - it's cheaper here to live than it is in other places like Bangkok, Pattaya, Phuket," Justin said, referring to the capital and two top tourist resorts.

Holidaymakers in Thailand rarely venture to Isaan, the country's least prosperous region, where downtrodden farms are more commonplace than the glitzy hotels and paradise beaches found further south.

Yet many foreign men apparently share Justin's enthusiasm.

He and Eve are one of an estimated 60-70,000 cross-cultural couples now in the region according to Buapan Promphakping, associate professor in social development at the local Khon Kaen University.

The trend began back in the 1960s when thousands of U.S. soldiers were stationed in the area during the Vietnam War.

But it has continued apace, particularly as many poor Isaan women have left home to find work in the tourist hubs - often as bar girls - where they can meet foreign men and bring them back to settle in the northeast.

Justin's fiancee, whose full Thai name is Nirruttaya Yapha, said "the way of life is easy" with her Western partner, who even helps with the washing up, and together the pair now run a small clothing business.

But Justin's socialising with fellow expatriates is a sore point.

"He's not single anymore and when they go out at night, they stay out until the morning. It's not acceptable, so we fight regularly," she said.

There can be a darker side for both partners in these unions, in which big age gaps are common and Thai law means Western men often end up buying local properties in their wife's name.

"I mean, how smart do you have to be to realise that this could be a bit of a trap?" said John Burdett, a British lawyer-turned-novelist who has extensively interviewed Isaan bar girls in Bangkok for his books.

Burdett said Thai-Western marriages could, however, work "fantastically well" - and often provide a financial lifeline for the woman's family - if couples have the right approach.

"It's a question of both parties, especially the men, understanding that this is a very different culture and if you want a long-term relationship you're going to have to understand the culture," he said.

Ronnie Behnke, 37, is trying to do just that, after moving from Brisbane in Australia to his wife Parnom's quiet home village in the Isaan province of Khon Kaen, where the couple have set up a fish farm together.

"I was going into a jungle - you hear a lot of bad stories about people being ripped off," he said. "I just moved along step-by-step to make sure this is what I wanted to do."

Ronnie said he "hit it off" with his 26-year-old wife in the southeastern resort of Pattaya seven years ago, where he was on holiday and she worked as a housemaid, but he found his first visit to the northeast something of a shock.

"They had nothing, her family. The toilet was a disgrace so I fixed the toilet, the shower. They wanted me to stay at the house but I couldn't use it," he said.

"When I came here and saw people who have nothing to give, but they still give it, I thought: these are people I want to help."