Is it permissible for a suitor to ask his fiancée to touch her private parts and to utter words over the phone that suggest intercourse, and is this considered masturbation or adultery, and what is the ruling of Islamic law on this?

Masturbation is forbidden in Islamic law according to most scholars, and it has serious harms. The one who commits it is not considered an adulterer who incurs the prescribed punishment (hadd). One must repent and seek forgiveness from it by immediately ceasing the act and resolving not to return to it. There is no obedience to a creature in disobeying the Creator. It is disliked to speak with a man about matters of enjoyment over the phone for fear of others overhearing.