Formal:
* Mon prince: This is the most direct and formal translation, literally meaning "my prince."
* Votre Altesse: This is a very formal and respectful way to address a prince, meaning "Your Highness."
Informal:
* Mon petit prince: This is a more affectionate way to say "my little prince."
* Mon prince charmant: This is a romantic way to say "my charming prince."
Other options:
* L'homme de mes rêves: This translates to "the man of my dreams" and can be used as a romantic alternative to "my prince."
* Mon amour: This simply means "my love" and can be used in a romantic context.
The best way to choose the right phrase depends on the situation and your relationship with the person you are talking to.