James Franco generated major buzz at the Sundance Film Festival this year for his performances in “True Story” and “I Am Michael.” But the latter film has one scene that audiences were particularly eager to see: a threesome involving Franco and his costars Zachary Quinto and Charlie Carver.

For Franco, the sex scene was NBD, which he attributes to his involvement in other movies about gay experiences — such as “Milk” and “Interior. Leather Bar.” — as well as his costars’ comfort with the material.

When Vulture asked Franco about the threesome, he said it was way easier in comparison to another gay sex scene he filmed, for 2011’s “The Broken Tower,” with Michael Shannon.

“It was very different. I had to take [Shannon] to dinner before we shot it because he was so uncomfortable,” Franco dished. “He was like, ‘We've gotta talk about this.’ So I went in to New York, and as soon as we sat down, he was like, ‘Aw, now I feel stupid that I'm such a wimp. All right, I'll do it, I'll do it.’”

But once they got to set, Franco says, Shannon’s nerves kicked in again.

“We did one take, and if you look closely at the scene, you'll see that I am pulling his face close to me because he [refused to get close], and we're supposed to be passionately making out,” Franco told Vulture. “And he's a strong dude! But in the end, it worked. Half-assed love scenes are the worst. Straight or gay! So I was just doing my job on [‘I Am Michael].’”

But what if it had involved someone like Danny McBride, who’s starred alongside him in raunchy comedies like “Pineapple Express” and “This Is The End?”

It may seem like an out-of-this-world possibility, but Franco revealed that it almost happened ... for real. Franco said that he and McBride were initially attached to another Sundance flick, “The D Train,” which includes a sex scene between their would-be characters, but the roles eventually went to Jack Black and James Marsden.

“One of the reasons that I was originally interested in ‘The D Train’ is because Danny is uncomfortable with that kind of material, so there would be a real situation there, I thought, where he would actually be uncomfortable doing that sex scene and playing out the aftermath,” Franco said. “Not that he's homophobic, but just engaging with that himself, he would just be uncomfortable, I know. There are things in ‘Your Highness’ that he wouldn't do, even for a laugh!”

So, alas, we were all swindled out of a steamy Franco-McBride bedroom sesh. Guess this’ll be as close as we ever get.