The previous record -- 32 hours, 7 minutes and 14 seconds -- was set in 2009 by a couple in Germany, according to Guinness World Records.
Fourteen mostly Thai pairs entered the contest when it kicked off Sunday morning at 6 a.m. local time. By Monday afternoon, half were still puckering up on the white-marble corridor a shopping mall, where tourists gawked and smiled at the spectacle, snapping pictures with glowing mobile phones behind a red rope.
"We didn't think we would find anybody that could break the record," said Somporn Naksuetrong, the manager of Pattaya's Louis Tussaud's Waxworks museum, which organized the competition. That seven couples apparently did, he said, "is amazing."
By late Monday evening, three more pairs had dropped out and four couples were still left smooching. The last left kissing wins a diamond ring worth 50,000 Thai Baht (1,606 dollars), and a 100,000 Baht (3,213 dollar) cash prize.
According to the rules, the lovebirds' lips cannot part at any time. They are allowed to drink things like water, coffee, milk or juice -- but only through straws while continuing to kiss. They also have to remain embraced during bathroom breaks possible every three hours -- accompanied by contest monitors.
The harshest rule: no sitting or sleeping. One woman participating with her boyfriend fainted just half an hour after it began Sunday.
Despite its reputation for having one of the biggest sex industries in the world, Thailand is still a conservative nation where kissing in public -- even a small peck -- is frowned upon. Participants had to show proof they were either married or truly a couple -- a letter from both parents or a marriage certificate was acceptable.
"We want to show that love is meaningful and powerful," Somporn said. "It's not easy to stand there and kiss for that long. They really have to help each other and support each other."
A Thai and international soundtrack that included tunes like Sixpence None The Richer's 1997 hit "Kiss Me" kept couples swaying overnight, some barefoot or in yoga-like poses.
About 35 hours into the marathon, 37-year-old Preedi Singhajan scribbled a note on a paper tablet to his 51-year-old partner, Rungnapa Rojananawin.
"Can you go on?" he asked.
She soon answered by ending their embrace. Attendants swiftly sat the couple down and a nurse took Rojananawin's pulse.
"The competition is fierce," she said, slumped in a metal chair as five other couples shimmied in a bizarre scene akin to a high-school dance tempered by bright floodlights. "These people aren't giving up easily."
Louis Tussaud's Waxworks -- a Pattaya wax museum, is under the management of Ripley's World of Entertainment. Representatives of Guinness World Records were not immediately available to comment, but Somporn said they were aware of the contest.
The couples who took part were mainly Thai and ranged in age from 21 to 51. There was one German man with a Thai woman, and also a gay couple.
The record for the longest kiss was set by Nikola Matovic and Kristina Reinhart in Germany in February 2009, according to Guinness, whose officials will have to verify the latest milestone for it to become official.
