What a mess "Miss March" is. And I'm not just talking about the repeated involuntary bowel-evacuation moments.

A cut-rate Apatow-ish raunch comedy by a bargain-bin Paul Rudd (Zach Cregger) and a Jason Segel/Seann William Scott wannabe (Trevor Moore), this Playboy fantasy farce is one of those painful comedies in which the strain to be funny shows.

The stars of fringe cable TV's "The Whitest Guys You Know" co-star, co-wrote and co-directed this comedy about two mismatched pals who take a road trip to see the ex-girlfriend who became a Playboy playmate.

Eugene (Cregger) is the nerdy guy who co-hosts abstinence lectures in middle schools with his chaste girlfriend, Cindi (Raquel Alessi). They're saving themselves for marriage. Or at least prom night. But on his way to a reluctant coupling, Eugene gets drunk, falls, bonks his head and slips into a four-year coma. Best-bud Tucker (Moore), the guy who got him drunk, revives him with a whack on the head with a baseball bat and takes his atrophied pal on a road trip to the Playboy mansion, where Cindi has gone from Miss Purity to Miss March.

Scruffy moments and scruffier characters in this movie work. There's the classmate-turned-rap star (Craig Robinson, always good for a laugh), the repeated Eugene-is-too-weak-to-stand moments, the furious girlfriend (Molly Stanton) who has fireman friends all across America trying to chase down and kill Tucker, all for a date that went horribly wrong.

And the abstinence lectures, complete with VD photo illustrations, are worth a giggle.

But the road trip that is the heart of the movie is as dull as the real drive from middle America to the Playboy Mansion. Yes, hot lesbians pick up the lads hitchhiking. As always.