Patrick McGillicuddy was returning to the Los Angeles church where he works as a youth pastor a few weeks ago when he grabbed a Diet Coke from the fridge. The can he pulled from the 12-pack read: “Dad.” The text message that started it all.

“What are the odds?” he wondered aloud. Patrick and his wife, Whitney, are parents-to-be. In fact, they’d just returned from their first ultrasound appointment.

“I immediately took a photo of the can and sent it to Whitney,” Patrick, 25, recalled. The text read: “I’ve got a fun idea for our announcement video.”

The creative couple — Whitney is a photographer studying to become a family therapist, and Patrick moonlights as a DJ — quickly came up with a concept for a 90-second video and shot it in Patrick’s parents’ backyard.

“It literally was just me, Whitney and a tripod,” Patrick says of the shoot. “The whole process, including editing, took about three hours.”

In the playful clip, the couple takes on the voices of the first names on the cans of Diet Coke they sip from. The emotional kicker comes when they rotate the final pair of cans to reveal the names “Mom” and “Dad.” In the final seconds, they scream with excitement before holding up their ultrasound photo.

They originally planned to share the film only with family and close friends, but the unexpected response convinced them to post it on Patrick’s YouTube channel on July 31.

“We thought it would maybe get 200 or 300 views,” he says.

Boy, was he wrong. The McGillicuddy’s network shared the film on Facebook, and things quickly snowballed from there. By Monday, more than 1 million people had watched it. By Tuesday, the media had caught on — from a local radio station in Louisiana, to E! Online andThe Huffington Post. Even PerezHilton.com blogged about the video, which as of press time had more than 2.6 million views.

“People have been sending us articles all week,” Patrick says. “We’ve been blown away by the response, and most comments have been positive. People are really excited for us.”

The Diet Coke team sent a congratulatory tweet, then thought the couple might need some inspiration picking a name for their new addition, due to arrive in February. So the team shipped them a year’s supply of their favorite drink — featuring the most popular names in the U.S. on the 20-oz. labels. Watch the special delivery.

When asked how they’ll top their viral hit in the coming months, Patrick, who admits to being more extroverted than his wife, laughs. “We’ve been talking about it,” he says. “I, of course, love attention and immediately suggested doing videos for the gender reveal, name announcement and birth… but Whitney was like, ‘calm down.’”

So for now, the McGillicuddys are savoring the moment and preparing to become first-time parents.

“I think it’s cool that one day we’ll get to tell him or her that ‘millions of people were excited you’d be entering the world,’” Whitney says