Earlier this month we told you how Napster founder Sean Parker tipped a West Hollywood waitress $5,000 during a big night out with friends. Turns out Facebook founder Mark Zuckerberg was one of those friends, and the night ended with him and Parker in a drunken "screaming match."

Parker, Zuckerberg and their buddies reportedly dropped six grand at the Beverly Club in West Hollywood three weeks ago. But things got testy when Parker and Zuck started arguing, according to the New York Post.

The beef was about technology, of course: Parker is an investor in the music service Spotify and is largely responsible for its recent integration into Facebook. (As you may remember from The Social Network, Parker was an early investor in Facebook.) But Parker is apparently not happy with all the details. A Post source told them:

"Sean argued that all Spotify users should not be forced to sign up for a Facebook account, but Mark wouldn't budge. It was a full on screaming match outside the club, but stopped short at coming to blows. They then stormed off in different directions."

Parker is a notorious hot-head—he recently took his bullshit machine to Twitter, asking if Occupy Wall Street is "anything other than an excuse for bored (possibly unemployed) people to have a great big party?"

But this is a different side of the imperious Zuckerberg we see taking long, woodland strolls in the press. At heart, it seems, he's still a booze-swilling tech bro, bumping chests over the logistics of an app. (By the way, Sean Parker is right.)

[Photos of Parker (left) and Zuckerberg (right) via Getty Images]