An Italian man who reportedly broke the world record for non-stop kissing had to receive oxygen after his efforts.
Organisers admitted they thought the "kissathon" was difficult
Officials at the St Valentine's Day "kissathon" in Vicenza, northern Italy, said Andrea Sarti kissed girlfriend Anna Chen for 31 hours 18 minutes.
After his marathon kiss Mr Sarti has to be resuscitated with oxygen by a first aid team while Ms Chen had to lie down.
Mr Sarti reportedly entered the competition for the $12,700 prize money so he could marry Ms Chen.
Competition rules were strict, with couples required to remain standing throughout the kiss.
They were not allowed to eat, drink or go to the toilet, and could communicate only by using written or text messages, the UK's Guardian newspaper reported.
In addition to breathing problems, Mr Sarti also suffered cramp, which Ms Chen attempted to alleviate by massaging him.
"It was really difficult," organiser Lucaino Gaggia was quoted by the Guardian as saying.
"We didn't think they could do it.
Their secret was concentration... and the ability not to think about time passing."
If confirmed by Guinness World Records, the kiss beats the previous record of 30 hours 59 minutes, set by an American couple in 2001.
Meanwhile, in Rome, thousands of gay couples kissed each other in the historic Piazza Farnesse to call for legal rights for same-sex couples.
The mass kiss itself only lasted about 10 seconds.
But BBC correspondent Tamsin Smith says people taking part hoped to send a more lasting message of protest to Italy's political and religious establishment.