LOS ANGELES, CA — Seth Rogen seems to be doing things backwards these days. First he made a baby with Katherine Heigl in the box-office hit Knocked Up. Now, according to Celebrity News Service, he plans to make a porno.Shouldn’t the porn have come before the sex? Whatever. We’re beginning to feel sorry for the guy: It appears the only time he gets any is when the chick is drunk or desperate for cash.

A brief item in the trades last week reported Rogen and Elizabeth Banks have signed on to star in director Kevin Smith’s new project, Zack and Miri Make a Porno. According to pre-production buzz, the film follows two friends (Rogen and Banks) who, facing separate financial crises, decide to leap at the old maxim “sex sells” and enlist their friends to help them make an adult video. Along the way, they realize they care more about each other than either realized previously. Hilarity ensues.

Smith is the evil comedic genius who wrote, directed and co-starred in the cult hits Jay and Silent Bob Strike Back and Dogma.

No one at production company View Askew Productions was available to comment, but we wonder if any adult-entertainment industry insiders will contribute to the film.

Zack and Miri Make a Porno allegedly will film in Pittsburgh, PA, and be released in 2008.