It's the story we never knew behind George Clooney's thriving tequila company, Casamigos.

Clooney and pal Rande Gerber love tequila. They love it so much, the longtime friends decided to make their own: the perfect tequila -- so smooth that they could drink it just how they like it -- neat.

Loosely translated, Casamigos means 'House of Friends', named after the property in Mexico that Gerber and Clooney share.

Casamigos debuted in the U.S. in 2013, but it turns out the businessman and the movie star were actually "forced" into the venture.

Gerber tells ET he and Clooney spent two years developing Casamigos, and then two years drinking it. But one day, they got a call from their distillery, and were informed they had been ordering a whopping 1,000 bottles of Casamigos a year. Answers were needed.

"They said ... either you're selling it or you're drinking too much,'" Gerber explains, adding that he and Clooney were told they had to get licensed and "get legit" in order to keep producing their beloved tequila.

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Now, the venture is a burgeoning business, but its core message remains the same: friendship. Gerber's go-to toast? "To good friends." The company's new social media campaign is "House of Friends" and Gerber and Clooney want fellow tequila aficionados to share photos and videos of themselves enjoying Casamigos with their pals.

"George and I made the tequila ourselves and had a lot of good times coming up with the perfect one," Gerber says. "It was made by friends, for friends and that's what we're all about: friendship."

Watch the video below for how to make two amazing summer cocktails using Casamigos Tequila.