Relationship Manipulation

noun a person who schemes or plots, especially in a deceitful or underhanded way

• The conniver orchestrated a complex scheme to defraud the company.
• I can't trust that conniver, he's always up to something.
• That conniver is a real snake in the grass.
• The conniver's web of lies eventually caught up with them.

verb engaging in deceitful or underhanded schemes

adjective acting in a deceitful or underhanded way

• The conniving businessman manipulated the stock market for his own gain.
• I can't believe how conniving she is, always trying to get her way.
• That conniving snake tried to steal my lunch from the break room.
• Her conniving ways were like a spider weaving a web of deceit.