under the thumb{adj.} or {adv. phr.} Obedient to you; controlled by you; under your power.
The Jones family is under the thumb of the mother. Jack is a bully. He keeps all the younger children under his thumb. The mayor is so popular that he has the whole town under his thumb. Compare: JUMP THROUGH THE HOOP.
[TahlilGaran] English Idioms Dictionary ▲