Haven't Seen it Yet, But Plot Reminds Me...
...of "Personal Affair," with Leo Glenn, Gene Tierney, and Glynis Johns. Glenn's character, however, was above reproach, although he made a bad miscalculation in meeting alone with Johns, the student who was smitten with him. Apparently, "Term of Trial" (made almost a decade afterward) is darker and probably more psychologically complex than "Affair," and I'm looking forward to seeing it, although, alas, it's not showing up on Netflix.
BTW, one poster said that this might be the saddest character Olivier ever played. I'd have to see for myself, because, until then, IMO the saddest character he ever played was Archie Rice, in "The Entertainer," which I think is a truly great film.