You’ve seen it by now, maybe enough times to be sick of it: A man walks down a city street with his girlfriend, head turned backward, face curved into a Tex Avery ogle directed at a woman walking the other direction. This is the "distracted boyfriend" stock photo, an image that launched a thousand memes. And no one’s more surprised at its popularity than the man who took it.

Antonio Guillem is a 45-year-old photographer from Barcelona, Spain, who spends his days on shoots specifically destined for stock image companies. For most of that time, he’s worked with the same three models, though he says he parted ways with one of them a year or so ago. (Guillem declined to name his collaborators out of concern for their privacy.) His portfolio largely consists of people—some combination of two women and one man—in the sort of reactive poses that makes stock photography such an uncanny delight.

But in mid-2015, spurred by successful sales, Guillem wanted to diversify his look. “We decided to take a few risks, planning a session representing the infidelity concept in relationships in a playful and fun way,” he says over email. He and his models took to Gerona, an idyllic city in Catalonia, Spain, chose a spot on the street, and started shooting. “It was quite challenging to achieve face expressions that were believable,” says Guillem. “Mainly because we always have a really great work atmosphere, and almost all the time one of the models was laughing while we were trying to take the picture.”

While multiple shots came out of that session—and countless have featured the same trio over the years—it was “Disloyal man walking with his girlfriend and looking amazed at another seductive girl” that would go on to set the internet ablaze with infinite spins on the same formulaic joke.

The Meme Documentation Tumblr—yes, there is one, and you should follow it—traces "distracted boyfriend" back to the above late-January post in a Turkish Facebook group devoted to prog rock (the group's name translates to "Great Answers to Prog Enemies"). After that, it laid dormant until this month, when Twitter ran amok with it. Here are just a few examples, provided in the spirit of instruction and joy.

For Guillem, the explosive popularity of a photo snapped two years ago presents more of a curiosity than any kind of milestone. “I never thought that one of my images will be that popular,” he says. “I didn’t even know what a meme is until recently, when the models started to tell me about the memes that people were doing with our work.”