Woody Harrelson, Matthew McConaughey build on friendship with ‘Brothers’

“Everyone’s nice and lubricated,” McConaughey says, “and, all of a sudden out of nowhere, my mom says, ‘Oh, I knew your father, Woody.’ And the ellipsis was enough for even my 6-year-old son to go, ‘Oh, I think I know what that might mean.’”

Timewise, a relationship could have happened “because it would have been during my mom and dad’s second divorce. She would have been free to have a dalliance with somebody in West Texas,” McConaughey says. “He completely believes it’s true. I don’t.”

Harrelson has suggested DNA testing. Instead, the two friends are exploring the idea in a comedy.

“We’ve always had good chemistry,” Harrelson says. But the real fun is as friends. That friendship goes back years — to an agency party in Los Angeles or the set of “EDtv” where the two played brothers. Which story is true depends on who’s talking.

While McConaughey is likely to ramble, Harrelson is good at slipping in a salient comment. Both listen intently. Both are just waiting to pounce. When they presented at the Emmy Awards, Harrelson didn’t realize he should step to the side of the stage when the “Widow’s Bay” folks accepted their award. So when the producer begins her speech, it looks like he’s part of the cast.

Days later, McConaughey won’t let him forget the gaffe and calls him “red shirt Woody” to hammer home the point.

When the idea of “Brothers” emerged, there was talk of improvising — a la “Curb Your Enthusiasm” — “but it’s got to be quick,” McConaughey says. “Every little scene has a beginning, a middle and a punchline. And I am more of a long joke.”

“Yeah, he’s the long joke,” Harrelson says with a smile.

Comedy, the “Cheers” star adds, “is much, much harder than even doing a play or a movie. There’s something much more challenging about it.”

Then, too, McConaughey is more Method in his approach when they’re acting together. In “True Detective,” “he stayed in character the whole damn day. I wanted to slap him," Harrelson says. "It’s not until the end of the day where you can actually have a conversation with him. So, in this, since he’s playing Matthew McConaughey, it was fun. We were like unruly school children.”

Both say they had room to improvise on “Brothers,” “but we decided writers and scripts would be maybe helpful,” Harrelson says. “He wanted to go out and wing it. I said, ‘Dude, this is too (much of a) high-wire act to be winging it. I don’t want to be winging it.’”

While McConaughey’s mom was a stickler about television (“you couldn’t watch it”), Harrelson considers himself an addict. He can still recall his favorites (“Wanted: Dead or Alive”) and when the obsession ended (“when I finally went to college … and I’ve never been addicted to television since”).

When they started spitballing “Brothers,” Harrelson insisted they needed more jokes. “And he just kind of looks at me like, ‘Awww, you idiot. It’ll be situational humor.’”

“We have a lot of fun together,” McConaughey says. “But we also share … where we think we’re coming up short or where we want to be better men, better fathers, better husbands, better actors. We kind of always shared that.”

And, says Harrelson: “He’s got a lot of wisdom. There are many times where I come to him and need his guidance and it never fails. He comes through. He comes through strong.”

The secret to their friendship: “We both take a lot of internal pride in not being the one to tap out of a good time,” McConaughey says. “Or to be the one to tap out and go, ‘Oh, that’s going too far.’”