1. He perfidiously betrayed his friends by revealing their secrets to their enemies.
2. The spy perfidiously infiltrated the organization and gathered sensitive information.
3. She perfidiously manipulated her way into a position of power within the company.
4. The politician perfidiously promised to lower taxes, only to raise them once elected.
5. He perfidiously pretended to be her friend while secretly working against her interests.
6. The thief perfidiously gained the trust of the homeowners before robbing them blind.
7. The general perfidiously turned on his own troops in exchange for a pardon from the enemy.
8. She perfidiously spread rumors about her coworker in order to get ahead at work.
9. The con artist perfidiously convinced the elderly couple to invest their life savings in a fraudulent scheme.
10. The dictator perfidiously eliminated any potential threats to his power through deceit and manipulation.