Here's a very random thought: I find somehow "annoying" how the expression "to sleep with" is always used as a global and general metaphor for the two-headed monster.
I mean, on one hand I perfectly understand how it's less gross to say "to sleep with" rather than saying "having sex" or, as prude people say, "the F word", but I've seen countless situations where "X slept with Y" has been used even though the couple literally did not consumate the act in bed at all
I get that the most common situation is two people consumating it in bed at one's place and then the other partner stays the night... but this translated into that generic "sleeping with" that is used when there are no beds or sleeping involved
Also in Italy we have the same expression, the literal translation would be "to go to bed with", I would feel very weird in saying I went to bed with someone if all I did was a quickie in a car or whatever other situation.