What does the fortune teller mean by saying that my ex-husband is insidious?

The fortune teller said that my ex-husband was very sinister. It shows that your ex-husband's face is vengeful and easy to bite the hand that feeds him. It is a villain's face. When getting along with them, if knowledge touches or harms their interests, such men will try their best to calculate you and do bad things behind your back, and such interpersonal relationships will get worse and worse.

You can't figure out what they think, because they are always angry, insidious and government-driven. In life, they like to calculate others behind their backs.