XX/XY (2003)

One night at a party, Coles (Mark Ruffalo) meets college roommates Sam (Maya Stange) and Thea (Kathleen Robertson), and the three of them have a wild sexual encounter. However, when Coles and Sam start a relationship, it is soon ruined by jealousy and mistrust. Eight years later, Sam runs into Coles, which prompts a reunion with Thea. Although Thea is married and Coles has a live-in girlfriend, there are still unresolved feelings between them that put their adult lives into turmoil.