Sometimes, a kiss is just a kiss.
And sometimes, it's a sign of swift and sweeping cultural and political change.
Over the past days and weeks, same-sex kisses have started to arrive in mainstream news media.
"We're now seeing this stuff completely across the board," said Bob Thompson, director of the Bleier Center for Television & Popular Culture at Syracuse University. "This has been evolving for a long time."
Just five years ago, CBS's "The Early Show" blurred a kiss from Adam Lambert and his boyfriend during a musical performance on the "American Music Awards," deeming it "a subject of great current controversy."
The year before, Katy Perry titillated much of the country by merely singing that she kissed a girl -- and she liked it.
How times have changed.
On Wednesday, following the opening of the Allegheny County Marriage License Bureau to same-sex couples, the Pittsburgh Post-Gazette website featured a photo of two women kissing.
That same night, ABC aired a gay wedding of characters Mitchell and Cam on its hit show "Modern Family," sealed with a kiss afterward.
And earlier this month, ESPN showed Michael Sam giving his boyfriend a celebratory kiss after he became the first openly gay football player to be selected in the NFL draft.
The sports network actually aired its first gay kiss -- a celebratory smooch between a gay professional bowler and his husband -- last year.
To some extent, same-sex kisses have been prevalent in the media for some time.
There were same-sex couples on shows as far back as "Dynasty" and "Thirtysomething," said Mr. Thompson, with a then-controversial same-sex kiss on a 1994 episode of "Roseanne."
For a period of time in the 1990s, he said, same-sex kisses appeared with some regularity on network television, becoming almost trendy. "The same-sex kiss became one of those things that gave credibility to a show -- that it was serious, cutting-edge," he said, referring to television programs such as "Ally McBeal" and "Dawson's Creek."
Still, there has been a much more recent change in media showing same-sex kisses by real people, rather than fictional ones.
In some cases, those pictures have still been accompanied by controversy.
Both the Denver Post and the Fayetteville Observer newspapers ran editor's notes of explanation to readers who criticized front-page photos of gay kisses -- in Colorado, from the state House speaker and his partner after passage of a civil unions bills and in North Carolina after the first gay military wedding at Fort Bragg.
As long as the images aren't meant to shock but are a reflection of the news of the day, those are the images that the media should be using, said Al Tompkins, a senior faculty member at the Poynter Institute in St. Petersburg, Fla.
"If they got married on the first day the law allowed and they didn't kiss, it would be news," he joked. "If they stood there, they got married and they kissed each other, our job is to tell what happened."
The Post-Gazette received few, if any, complaints after using an image online of a same-sex kiss Wednesday.
Given that same-sex couples have been present on mainstream network television for decades, Mr. Thompson noted that it has actually taken quite a while for same-sex kisses to regularly appear in news media.
"By the time stuff made it to network television back in the network era, it meant that the controversy was kind of over," he said. "This is taking some time but it's happening -- there's no question about it."
Anya Sostek: email@example.com or 412-263-1308.