As a fledgling animator named Coles, Ruffalo crashes a party in the early 1990s, landing in bed with two college girls, Sam (Maya Stange) and Thea (Kathleen Robertson). But some desires are only surface deep, and the outcome is unexpectedly disappointing for everyone.

The movie then jumps ahead 10 years to find Coles directing commercials and comfortably ensconced with his girlfriend, Claire (Petra Wright). A chance encounter with Sam, who has just dumped her fiancé, reawakens old feelings that come to a head when everyone reunites for a weekend on Long Island.

The split narrative and unfettered visual style suggest that writer-director Austin Chick has a taste for French New Wave and 1970s American cinema, although the lack of grit in "XX/XY" and its seeming ambivalence toward its players makes for a shaky character study. "XX/XY" succeeds in generating emotional tension, even though it's lacking in pressure.