[probably NSFW] Can you think of any more films where the sex act is cleverly visually implied, but not overt?

I can think of two:

1) At the very end of Dragnet (movie) after Sgt. Friday (Dan Ackroyd) acknowledges that his girlfriend is no longer “the virgin Connie Swail”, the camera pans up to the LA Police headquarters building, which is clearly implying a large phallus.

2) At the end of North by Northwest (Hitchcock classic), after the scene on Mount Rushmore, Cary Grant and Eva Marie Saint are aboard the train going back east. The final scene of the movie is the silver train speeding into the small opening of a railroad tunnel (but is suggestive of something else).

Can you think of similar implied imagery in film?