We always use these: Ram or Ramming because of this scene from Ben Hur which we think of as a humorous metaphor for intercourse leading up to ejaculation:
"Send the Bishop to the Cloister" was one my parents used. "Bring the car in for service" is my wife's.
Since starting chastity, "sex" now has a slightly different meaning for us. "Shall we have sex? / Do you fancy sex?" now means "Time for him to give her an orgasm".
You've probably noticed I say "PIV" a lot (or as my wife pronounces it... "Pee in Vah-jee"). Gotta be specific nowadays since "sex" takes on a lot of meanings when you include oral, anal, fingering, pegging, reverse pegging, intercrural (thigh sex), leg-humping, etc.