But what if those engaging in that passionate smooch are a same-sex couple?
The Quebec government has launched a unique advertising campaign designed to get the province thinking about just how open-minded it really is when it comes to homosexuality.
The TV, radio and web campaign shows routine, everyday scenes in which the viewer has no idea until the end that the ad is about sexual orientation.
One shows a man texting his lover while awaiting him at the airport.
Then a man and woman exit simultaneously past the arrivals door. In the end, the woman brushes past and the two men join in a deep kiss.
Another ad shows a woman returning home to find a note from her partner. She is caught off-guard by a surprise party with a group of friends where she and her partner — a woman — share a passionate embrace.
In both cases, at the end, a narrator asks the viewer: "Does this change what you were thinking 20 seconds ago?"
The ads were developed by Cossette Communications in Quebec City over the past year. They're part of a $7.1 million, five-year anti-homophobia campaign by the provincial government.
The idea was not necessarily to shock the viewer but to get people thinking about how open-minded they really are, said Martine Delagrave, who oversaw the project for the ad firm.
"We learned in our research that Quebec is viewed as open to sexual diversity — but homophobia still exists and it still exists in Quebec," she said.
"Our idea for a first campaign was to shed some light, to have some awareness about how open we really are."
A survey conducted by the government suggests individuals tend to believe they are far more open-minded than society overall.
Delagrave said that while people are generally accepting, they are perhaps not as open-minded as they like to believe.
"We wanted the campaign to provide people with a first introspection — to let people say to themselves, 'If we have a ways to go, maybe I, personally, have a ways to go, too," she said in an interview from Quebec City.
The provincial government commissioned a survey of 800 Quebecers, in which 90 per cent described themselves as being open to sexual diversity.
While 78 per cent said they were comfortable with gays and lesbians, the number dropped to 45 per cent in the case of transgender people.
And 40 per cent said they're not comfortable with seeing two men kiss in public. More than one in two said they could easily recognize gays in public.
There have been some public complaints since the ads were launched last week.
To be specific, nine written complaints have reached the Quebec government since the ads went to air on March 3.
"The tone of the complaints (was that) many were jolted by the sight of two men or two women kissing in a government advertisement," said Paul-Jean Charest, a government spokesman.
"It revolves mostly around that."
There are other complaints on the web — some about the sight of homosexuals kissing, but also about waste of government funds.
Some Anglo commentators also linked the issue to language, fuming that the government is running a campaign about tolerance while spending public funds on the Office Quebecois de la langue francaise to crack down on English.
Many other commenters saluted the initiative, which stems from an anti-homophobia plan introduced by the previous Liberal government in 2009.
The government spokesman, Charest, said the ads were meant to trigger a reflection.
But the idea wasn't necessarily to shock and awe.
Delagrave said it's not uncommon to see gay couples in mainstream media these days.
“It's not a campaign that has a goal to shock. It's a Quebec government campaign, it's supposed to be positive," she said.
The campaign has reverberated elsewhere.
A bilingual website with the ads was launched simultaneously and it has found an international audience.
The website displays a series of scenarios with lesbian, gay, bisexual and transgender themes and it asks users how comfortable they are with each one.
Examples include a lesbian couple raising a child, or a bisexual physician.
In the first two days, the website had 131,000 visitors and 70 per cent completed a short, online survey. About a third of those who have completed the survey claimed to be under age 24 while the balance were older.
Of those who visited, 68 per cent were from Canada, 17 per cent were from France, three per cent were in the U.S. and two per cent were in Colombia.
The web page has also been retweeted a few thousand times on Twitter and received 32,000 "likes" on Facebook within its first 48 hours.
"It's got people talking and, if we were in a situation where everyone was entirely accepting, we wouldn't be talking about it," Delagrave said.
The government will conduct a second survey at the end of the campaign, to see whether there's been a shift in perceptions.
"We don't think that a four-week campaign will change everything, but we believe it'll take Quebec society farther down the path of openness," Delagrave said.
The campaign is being applauded by gay-rights advocates.
Laurent McCutcheon, president of Gai-Ecoute, says the fact that the couples are being portrayed in regular situations helps everyone relate to people with different sexual orientations.
"It's not aggressive, it shows a reality, and it shows an affectionate moment between two people," McCutcheon said.
"It shows a daily snippet, an everyday moment that's the same for everyone."
McCutcheon says there is still a need for such advertising campaigns — and the reaction of some people online this week proves it.
"For those who are reacting negatively, they are the ones who show that it is necessary," McCutcheon said. "It shows that people are not comfortable with this and so homophobia still exists.
When he recently launched the ad campaign, provincial Justice Minister Bertrand St-Arnaud described it as the first of its kind in Quebec, Canada and North America.
A second series of ads, revolving around issues like same-sex parenting, is planned for 2014 or 2015. The current ads run until the end of the month.
On the web: fighthomophobia.gouv.qc.ca
Also on HuffPost