Track 29 (1988) review

Miserable (and emotionally unstable) housewife Linda (Theresa Russell), whose husband Henry (Christopher Lloyd) is a gerontologist that spends his free time playing with his collection of trains and having an affair with Nurse Stein (Sandra Bernhard), finds herself aggressively pursued by hitchhiker Martin (Gary Oldman) who claims he's her long-lost son, and then the two of them engage in not-so-healthy physical relations.  Screenwriter Dennis Potter and director Roeg are trying to be naughty here, but this has less to do with actual psychology and more to do with proto-Tennessee Williams feminine hysteria (Linda was raped and impregnated when she was only a teenager), and it makes the truly questionable decision of allowing Oldman to bounce around and behave like a petulant man-child.  I'm not sure if the latest DSM has an entry in it regarding lonely women pretending to be seduced by their offspring, but that certainly warrants several decades of therapy, and all of the "is it real or is it in Linda's imagination" tomfoolery botches up the third act.