Je t'aime moi aussi mon Cher?

I love you too, darling (to a man)

the other correct way to say 'i love you too' would be "je t'aime aussi."

je t'aime means I love you and aussi means also or too.

for a person to say it to a man the ending would be "mon chéri"

for a person to say it to a woman the ending would be "ma chérie"

Précision by Crisdean

Mon Cher is often used in letter introduction (Dear Sir = (Mon) Cher monsieur)

It is a formal way.

Cher is used with people you know only with irony. So you cannot use it with a verb like Love.