I’ll start with an early one, from the Nic Roeg movie Don’t Look Now (1973). The movie revolves around the breakdown of the marriage between Donald Sutherland and Julie Christie after their daughter tragically drowns in an accident at their home. It’s a quite haunting movie actually, influential and groundbreaking at the time.
The love scene was unconventionally graphic for the time which lead to speculation that it was unsimulated, although I doubt that is true. Saying that, what woman could resist a haircut-tash combo like Sutherlands? The scene was also innovative because of the way it was edited, the sex being intercut with images of the couple getting dressed to go out for dinner, which was later paid “homage” to by Soderbergh in that Cloony movie he made with Jenny From The Block. This kind of unorthodox editing I remember most prominently from Sam Peckinpah movies (more to come on him).