Remember those old black and white movies, often romances, when everything was suggested or implied and nothing of a sexual nature was actually seen on screen? Probably a bit before your time. Everything is so much more explicit these days; nothing is left to the imagination. But you know the sort of thing I mean – the suggestion of a sexual encounter using a visual metaphor. For example: the couple on the train taking advantage of their otherwise empty carriage, look longingly into each other’s eyes, maybe a furtive kiss before they pull down the blinds. Then we cut to the train entering a tunnel.
Like I said: probably before your time.