think you own the place

think (one) owns the place

To behave in a haughty, arrogant, or imperious manner. The contractor they hired must think he owns the place, judging by the way he's telling us all how to do our jobs!
See also: own, place, think
Farlex Dictionary of Idioms.

think you ˈown the place

(also behave/act as if you ˈown the place) (disapproving) behave in a very confident way that annoys other people, for example by telling them what to do: What does she think she’s doing, coming in here acting as if she owns the place!
See also: own, place, think
Farlex Partner Idioms Dictionary
See also:
  • think (one) owns the place
  • stalk out of
  • stalk out of (some place)
  • (as) cocky as the king of spades
  • biggity
  • cocky
  • cocky as the king of spades
  • with (one's) nose in the air
  • with your nose in the air
  • get off (one's) high horse