Arnold Schwarzenegger recently revealed some fun backstory on how Sylvester ("Sly") Stallone initially recruited him to "The Expendables" action film series.

"One day, I was sitting at my hairdresser, and Sly came up to me, and he said, 'Oh, man, it would be so great if you could be doing just a little bit something in my "Expendables" movie,'" Schwarzenegger said during a recent panel discussion for ESPN's "30 For 30 Shorts" at a Television Critics Association event.

Schwarzenegger was "The Governator" of California at the time. He stressed to Stallone how important it was to film his part quickly, and over a weekend as to, in his words, "not take away from my work for the people because they will get very upset if someone would know that I'm shooting on Thursday and Friday in 'Expendables' and not doing the people's work."

[Related: 'Expendables 2′ poster reveals 573 years of action expertise]

When Stallone volunteered to call Schwarzenegger's agent to iron out the details, the former "Terminator" actor recalled his reply: "You don't have to call my agent. I make the decisions... So I'm in."

And when Stallone brought up salary negotiation, Schwarzenegger served him another zinger: "You don't have to pay me. I'm in... I'll do that for you."

And he did. Finally. You see, Schwarzenegger revealed he and Stallone had been looking to team up during the 20 years prior that led to that fateful day at the hairdresser. Whether a not-so-right script or scheduling conflicts -- something always seemed to get in the way, Schwarzenegger said.

[Related: 'Expendables 2' trailer brings second coming of Chuck Norris]

The two longtime friends have now attached themselves to three films in which they both appear -- both "Expendables" movies as well as upcoming sci-fi thriller "The Tomb."

Why so much "Ahnold"-"Sly" big-screen action all of a sudden? Because, as Schwarzenegger joked, "We're in love with each other."

"The Expendables 2" hits theaters next Friday, August 17. In it, Schwarzenegger reprises his role as the tough-as-nails Mr. Trench and, for example, rips the door off of a smart car, shoots down the bad guys and -- you guessed it -- puffs on a fat cigar while uttering a spoof of his famed "Terminator" line, "I'm back."

Arnold Schwarzenegger On ESPN '30 For 30'

'Expendables 2': Comic-Con Clip 'Expendables 2': 60 Second Trailer 'Expendables 2': Theatrical Trailer 'Expendables 2': Teaser Trailer

Follow me on Twitter