Can the suitor's knowledge of the beautiful places in a girl's body be interpreted, and does this indicate his relationship with jinn, and should this relationship be continued?

If the young man is righteous in his religion and character, then accept his proposal, based on the saying of the Prophet, peace and blessings be upon him: "If someone whose religion and character you approve comes to you seeking marriage, then marry him. If you do not do so, there will be tribulation on earth and widespread corruption." As for his claim of knowing your body, that might be through a relative informing him, or someone who saw you when you were young, or he might have dealings with jinn. You must verify his condition, and if it becomes clear that he has an unlawful relationship with jinn, then do not accept him as a husband. Also, it is not permissible for a woman to speak with a non-mahram man without necessity, even if he is a suitor and via phone, until the marriage contract is concluded.