Cherie
"Sweetheart" is most often rendered as "Chérie" (fem.) and "chéri" (masc.) in French.
The Latin word for sweetheart is puella. The word sweetheart in Spanish is novio, in Italian it is Tesoro, and in French it is amoureux.
Cheri/e
Mon chéri.
In Cajun French, you can say "cher(e)" or "mon cher" to mean sweetheart.
Merci chérie
bien-aimé
amoureux
cheri occupés.
ma petit chou
Là où êtes vous amoureux
ce qu' une petit amie