KEY POINTS:
Looking to pucker up to a potential partner under the mistletoe this Christmas?
Well hold that thought, because a study by US academics reveals a bad first kiss could very well be a relationship killer.
Two-thirds of women and 59 per cent of men quizzed by researchers at the State University of New York admitted desire disappeared after the first smooch.
Kumeu-based sex therapist and online counsellor Chris Hight blamed pheromones and other "feel-good drugs" released by the brain when we are emotionally aroused.
"If the experience doesn't match what the brain has set up, then the let-down is going to be greater," he said.
"It's the build-up to it, combined with all the chemical reaction in the brain. If the build-up is big, then the letdown's going to be big."
Social and cultural pressures also play a part.
"With a lot of what's on television these days, and the intimate stuff that we watch, people build up an image of what a first kiss is going to be like.
"If it falls short, then people will back off. They think if you're no good at kissing, then you'll be no good at anything.
"For women, too, it depends on what has happened up to that moment, the level of flirting, the game that goes on beforehand that builds the anticipation."
Take a bow then All Black Andrew Ellis, who must have done the right thing.
He and his girlfriend Emma Bainbridge have been together since they met as 15 and 16-year-olds seven years ago.
"I can't remember any other first kisses," admitted Bainbridge.
Canterbury psychology professor and relationship scientist Garth Fletcher said the finding was "intriguing".
"I wonder how awful a kiss has to be to put you off someone you really like."