well if she has made it clear she loves you in a platonic way leave it at that
not being mean but love comes in many ways
i love my wife one way i love my kids another and yes i love my friends in a completley different way if that makes sence
if she has said platonic well i would stick with it that way unless you and your wife are comfortable with swinging and are secure enough in your relationship... if that makes sence
hope i helped some
Hugs Joe