Neil LaBute has several reasons to be happy about Reasons to Be Pretty: It got him to Broadway, with a Best Play Tony nomination and noms for half of his four-person cast.

What he thought he was doing with this blistering comedy about two sets of lovers crashing and burning was to cap a toxic trilogy on how one's looks distort values — a point he made in The Shape of Things and Fat Pig. What he seems to have done, however, is open a can of cobras that unleashes the ongoing sex saga of an odd quartet who fell apart over what's pretty and what's not.

Round Two, Reasons to Be Happy, officially opened June 11 at the Lortel. This is the first time LaBute is recycling characters, and he hinted there might be a trilogy in them, maybe even more.

"They're the kind of characters you must check in with every few years," he said, referring to the drama-prone foursome Greg, Steph, Kent and Carly. "This takes place three years later. They've moved on, sorta."

On that "sorta" hangs another anguished, combustible tale. It seems Steph — who took profound umbrage at being called "regular" rather than "hot," and thus created the tsunami that swamped both relationships — now feels she may have been a tad rash in her rage and is capable, in spite of her new marriage, of relapsing with Greg, the ex who has now taken up with her best friend, Carly. Naturally none of this sits well with Carly's ex, Kent, despite his new relationship. Josh Hamilton — who inherited the role of Greg from a Tony-nominated Thomas Sadoski — contended that the character is a decent sort, "but he gets himself into situations because he's too much of a pleaser. Part of him wants to say what he thinks the person he's with wants to hear, but he's not so good at saying what he wants. In this play, that causes him to spread himself too thin. I think that's indicative of how one can go through life with good intentions, and leave behind a trail of carnage. Even if you're not out to hurt anyone, it's very hard to go through life without bumping up against them in some way here and there."

Fred Weller follows Pablo Schreiber and Steven Pasquale in the role of Kent. "My character has changed substantially between the two plays," he noted. "He was a certified jerk in the first one... but it's three years later, and he's full of inner regrets, having lost his wife and child. At the end of pretty, she was pregnant, and Greg sent her home to catch me cheating — in effect, breaking up that marriage. Kent subsequently moved in with the girl he cheated with and discovered she's no good. He's [still this] angry, still fundamentally benighted guy, but with an awareness and guilt that haunt him."

Playing his ex, first played by Piper Perabo, is Leslie Bibb, making her New York bow. She made her stage debut last July at Williamstown in Neil Simon's Last of the Red Hot Lovers. She didn't see the previous reasons — and counts that a good thing. "It feels like this play is very different from the other one. The characters seem to have evolved. It is three years later. The relationships — all the dynamics — have changed. I'm not the same person I was three years ago, and I think that evolution is interesting to see. If you didn't see pretty, it's okay. You can come in and still get a sense of these people."

Fresh from nine seasons of "The Office," Jenna Fischer has some pretty big shoes to fill — Alison Pill originated the role of Steph, and Marin Ireland was nominated for a Tony for her turn at it — while making her own theatre debut.

"It's daunting and terrifying and exhilarating," she admitted. "In television, we would get maybe 15 to 30 minutes to rehearse something before we put it to film forever and all time. I'd love to keep doing theatre for a while — and only theatre for a while. Having Neil direct the material has been really special. He writes so well for actors because all of his characters are so complex, so flawed and funny. My character, even though she's married, feels Carly's not entitled to date Greg. There's still a code — right? — that you just don't do that, and so I confront her about it. Throughout the play I realize I want him back, and I'm willing to give up my marriage for him."

In the plays of Neil LaBute, nothing is ever easy — except, of course, the sex part.