Junkhearts (2011)

Frank is an ex-soldier, haunted by a violent past. He lives alone, drowning his nightmares with alcohol. Christine - smart and successful... on the surface, tackles life as a single working mother by immersing herself in drugs, parties and sex. Lynette, a young rough sleeper watches Christine stumble out of a club whilst she sits in the cold waiting for loose change to fall on her lap; her luck seems to change when she meets Frank who despite his misgivings, offers her a place to stay.

Source: TMDb