To add to others:
We use the neuter to address or refer to someone cute; desexing them is infantilising them, and infantilising them is a sign of affection, even if you are otherwise sexual with them. It’s the same thinking as using baby or babe in English.
So χρυσέ μου “my golden one” (masculine) or χρυσή μου “my golden one” (feminine); but just as often, χρυσό μου “my golden one” (neuter).
I have a soft spot for μάτια μου “my eyes”.
Κανακάρη μου (masc)/Κανακάρα μου (fem) is “my darling boy/girl”; that’s much more mother to son, and it’s derived from the verb for pampering.