Entertainment

DESPERATION FORNICATION

‘NIGHTS and Weekends” doesn’t waste time with foreplay. Within the first two minutes, Greta Gerwig and Joe Swan berg – the co-stars and co-directors – strip, tumble onto the hardwood floor and go at it with fervor.

Their characters haven’t seen each other in months, so you can hardly blame them. Gerwig’s Mattie is a nursing student in New York and Swanberg’s James designs video games in Chicago, so they have to take advantage of every second together.

“Nights and Weekends” is the latest entry from the mumblecore school of filmmaking – low budgets, handheld cameras, improvised dialogue, minimal scripts and male and female nudity are the trademarks.

(“Hannah Takes the Stairs,” in which Swanberg directs Gerwig, is another example.)

Mattie and James bare all a few more times as “Nights and Weekends” tracks their long-distance affair over a year.

Besides making love, the personable 20-somethings frolic in the rain, eat pizza, have a serious discussion in a stairwell, visit relatives and go to a photo shoot.

We also get to see Mattie wiping herself on the toilet, if that’s of any interest.

Gerwig and Swanberg seem to be in every scene. Other people pop up, but they quickly disappear without leaving any impression.

This movie belongs to its stars, who also wrote and produced. You can’t say their acting is good or bad because they are not really acting. They’re just being themselves, pubic hair and all.

NIGHTS AND WEEKENDS

The naked truth.

Running time: 79 minutes. Not rated (sex, nudity). At the IFC Center, Sixth Avenue and Third Street.

vam@nypost.com