Proclaimed two of comedy’s new legends in a recent issue of Vanity Fair, Rudd, 39, and Segel, 29, have shared the screen twice in the past, as supporting players in Knocked Up and more recently as mismatched surfing partners in last year’s Forgetting Sarah Marshall, which Segel wrote. But never before have they shared top billing, as they do in I Love You, Man, a platonic romance about a pair of incipient bosom buddies.

In the movie, their characters find a common bond in their mutual love of Rush, the Canadian prog-rock trio that Segel jokingly calls “the J.R.R. Tolkien of bands.” In real life, though, their friendship is rooted in a passionate devotion to what they do.

On their favorite topic of conversation:

JS: “Paul and I are students of comedy, and I think it’s fair to say we’re both comedy dorks. We love things like The Mighty Boosh and Little Britain, and we’ll constantly quote lines to one another. That’s how we initially bonded.”

PR: “I like Withnail and I. Have you seen it?”

JS: “Of course I have, it’s amazing! Have we talked about that?”

PR: “No, but we’re going to just as soon as this interview is over.”

On sharing the set with Rush, who make their big-screen debut in I Love You, Man:

JS: “Our characters bond over Rush. I love Rush, but I was a little too young to experience them in their prime. I learned about them during Freaks and Geeks because my character was a huge Rush fan, and I had to drum ‘Spirit of the Radio.’ Paul, however, is a huge Rush fan.”

PR: “Rush scared me when I was a little kid. I saw the ‘Tom Sawyer’ video and I was scared as hell. [Lead singer] Geddy Lee can be a really intense figure to a six-year-old. And a 15-minute drum solo can be scary as hell, too. But then I got into them, and it was really nice to meet them. There’s a mystery about them. They’re very reclusive. They sing about warlocks.”

JS: “Talk about the scene we did with them.”

PR: “In the scene, Jason and I are dancing around like crazy, and [co-star] Rashida [Jones, of The Office] is acting bored. I was hypersensitive that these guys were going to have a bad time or think that we were mocking them. So I took Geddy aside and I told him, ‘Look, we’re going to be dancing around, and she’s going to act like she’s not into it.’ And he said, ‘Oh, so it’s going to be like every one of our concerts.’ Well played, Geddy.”

On Segel’s decision not to pose nude on the cover of Vanity Fair after baring all in Sarah Marshall:

JS: “Vanity Fair wanted to still be able to sell magazines, and there’s nothing particularly appealing about me, Seth Rogen and Jonah Hill naked in a magazine. Paul has never looked better in that photo, and I can’t help but wonder if that’s because of the context. Anyone would look good next to me, Seth and Jonah in silk stockings.”

PR: “They should call it Vanity Hair. I just came up with that.”

JS: “People ask me if I Love You, Man is a romantic comedy, and I tell them, ‘Yes, it’s like When Hairy Met Hairier.’ I’m smooth like a baby’s head. Or is it a baby’s bottom? Is that the expression?”

PR: “I’m not touching that, sorry.”

On their mutual decision to seek out projects together:

JS: “We were sequestered at the hotel in Hawaii where we shot Sarah Marshall. At night we’d just collide at the pool bar – there were a lot of Mai Tais consumed, so collide is the right word – and we got to know each other. Most of the scenes we share in that movie were improvised, and we began to realize that we might make a good comic duo because we bounce off each other really well. There’s nothing better than having somebody you can play verbal ping-pong with on a comedic level, and Paul is the quickest guy around. He’s also one of the nicest. I’m heterosexual through and through, but the guy is dreamy.”

PR: “Jason is really funny. We riffed a lot in Knocked Up, mostly in scenes that didn’t make it into the movie. None of it was that funny, I suppose, or else it would have been in the movie. But that was the first time we sensed we could play off each other.”

JS: “We’re trying to bring it back to the old-school comedy teams, and next year we’re releasing Paul and Jason Meet Frankenstein.”

PR: “I haven’t read the script yet.”

On working with Judd Apatow’s unofficial comedy troupe, of which Segel is a longtime member:

PR: “It’s been really cool to break into this group that’s existed for a long time with Judd and the Freaks and Geeks guys. I hope it continues, it’s been really fun.”

JS: “The reason I’ve said Paul was so nice to do Sarah Marshall is that Paul is a leading man, and he was willing to work on that movie because he loves acting and he loves comedy. He shot for a week, and he was only in a few scenes.”

PR: “Hey, I was really excited to work with you. And I love Hawaii.”

JS: “I think it speaks to your character, what kind of actor and friend you are.”

PR: “Thanks, buddy.”

On the term ‘bromance,’ and its relevance to the concept of I Love You, Man:

PR: “It seems like bromance just came out a couple months ago, and when we were working on the film none of us had ever heard of it.”

JS: “It’s really annoying, isn’t it?”

PR: “Yeah, but that just happens. Somebody asked me the other day if we are ‘manpanions.’ So there’s a new one.”

JS: “One of the things I love about the movie is that it’s not a cynical look at these relationships, and it’s not a wink-wink, nudge-nudge jokey version of them. We tried to do a very natural, realistic depiction of a guy trying to find a new friend and then layer funny on top of that. We didn’t want to make the funniest version of that story. We wanted to do a realistic version and have that be funny.”

PR: “We didn’t want it to be over the top.”

On playing Peter Klaven, the straight man to Segel’s uninhibited layabout in I Love You, Man, and the character Rudd identifies with more than any other he’s played:

PR: “There’s a kind of open-mindedness to this character that I like. He’s well-meaning, and he often wears his heart on his sleeve, but there’s something bumbling about him. I relate to Peter in many ways. As for being the straight man, I like reacting to people, so I don’t think so much in terms of comedy or drama, straight man or… not-straight man.”

JS: (laughs hysterically) “Not-straight man? I think that’s my new favorite superhero.”

PR: “That didn’t come out right.”

JS: “This was the problem on the set. One of us would make the other laugh for 45 minutes and we’d have to stop shooting.”

PR: “I just don’t think I’m funny enough or even good enough to play the super-crazy funny guy. I’m more the setup guy, but I think you can find lots of humor in the setup.”

JS: “You’re definitely not the setup guy in Sarah Marshall. I think you’re selling yourself short. You’re the most diverse actor I’ve ever worked with.”

PR: “I – thanks. That sounded really insincere. Thank you very much. I really appreciate that.”