s'envoyer en l'air *
* to send oneself to the air
Expression used often by Everyone
Noun • To have sex, to get laid.
Note: The meaning can also mean killing yourself, in a sentence like "Je vais m'envoyer en l'air"
"Mon voisin passe son temps à s'envoyer en l'air, et il n'est pas discret."
"My neighbour spends his time sending himself to the air, and he is not discreet."
9 out of 12 French speakers have heard this