Both of the couples in John Curran's "We Don't Live Here Anymore" are living passionate, exciting sex lives. Unfortunately, they're living them with each others' spouses.

		'We Don't Live Here Anymore' Rating: R for sexual content and language Starring: Mark Ruffalo, Laura Dern, Peter Krause, Naomi Watts Director: John Curran

Based on short stories of adultery by "In the Bedroom" author Andre Dubus, it's a low-budget, tight-focus film that follows the tightly focused affairs of four friends. Set in a Washington state college town, the 30-something men are professors whose careers take precedence over their wives and families. They jog together, drink beers after work and surreptitiously bed each other's wives. The women are best friends, confiding about extramarital dalliances but leaving out one crucial detail.

The affairs themselves aren't the crux of Curran's character study. "We Don't Live Here Anymore" is really about the way each character conducts the affair: cautiously, brazenly, willfully or accidentally.

Mark Ruffalo is convincing as a passionate partner in carnal excess who carries his guilt on his sleeve. Peter Krause and Naomi Watts play it cool as a couple who have all but given up on rescuing their strained marriage, and Laura Dern is a whirlwind of conflicting emotions as a woman indulging in an act of extramarital revenge.

Director Curran fills his tight shots with increasingly violent railroad imagery that seems to foreshadow an impending four-way train wreck of exposed affairs.

The inconclusive solution, however, is as disappointing as a failed marriage.