Let's get this out of the way: Jim Carrey and Ewan McGregor make just about the cutest, most gaga-in-love couple we'll likely see in any movie at Sundance.

It was a happy discovery, made last night along with a giddy crowd of about 1200 at Park City's Eccles Theater for the world premiere of I Love You Phillip Morris. Based on the book of the same name, Morris is the too-strange-for-fiction story of Steven Jay Russell (Carrey), a brilliant Texas con man and prison-escape-artist extraordinaire, who falls deeply for a sweet, blonde Southerner he meets behind bars (McGregor).

Writer/director team Glenn Ficarra and John Requa, the pair who wrote Bad Santa, seem aware that what they found in this wildly unlikely true story—"It really is," a title card insists—is a storytelling goldmine. Their genre-bending script manages the seemingly impossible, ably juggling madcap Coensian crime farce, raunch comedy (with Leslie Mann playing Russell's dumbfounded ex-wife for good measure), and a matter-of-fact gay love story as poignant and frank as anything we found in Milk. No, the camera does not cut away from their passionate kisses or acts of fellative love; dare we say Morris contains some of the most sensitive images of bitch-on-inmate affection that have ever been captured on film.

Ficarra and Requa managed to rein in Carrey's malleable and frequently unhinged skill set, which nicely suits the character's penchant for heart-on-the-sleeve flamboyancy. And while starry-eyed romanticism isn't new territory for the star of Moulin Rouge, the always-surprising McGregor tries something new by allowing himself to become the more passive, pursued half of a doomed entanglement. His Phillip starts out all batted lashes and soft edges, but by the time Russell has pulled his final grift—one of a series of spectacularly executed cons that the audience itself never sees coming—a betrayed Phillip turns ferocious, and ultimately heartbreaking.

The film has yet to find a distributor, leading Ficarra to ask of the appreciative crowd, "Who's buying?" at the post-screening Q & A. A little bit later, Requa revealed some of the mysteries of the feature film casting process, deadpanning, "We sent Jim the script. He said yes. Then we sent Ewan the script. And he said yes."

We're extremely glad they did.