flash somebody a smile, look, etc.

flash (one) a look

To look at one, usually quickly and perhaps unexpectedly. That guy over there is so cute! Geez, don't stare, just flash him a look.
See also: flash, look

flash (one) a smile

To smile at one, usually quickly and perhaps unexpectedly. She was sad this morning, but I think she's feeling better now—she flashed me a smile before she left.
See also: flash, smile
Farlex Dictionary of Idioms.

flash somebody a ˈsmile, ˈlook, etc.

smile, look, etc. at somebody suddenly and quickly: She flashed him a quick smile, then was gone before he could say anything.
See also: flash, somebody
Farlex Partner Idioms Dictionary
See also:
  • flash (one) a look
  • look ahead
  • give (one) the eye
  • give someone the eye
  • give the eye
  • like a flash
  • dragged through a hedge backward(s)
  • fix (one) with a look
  • have a look-see
  • get a dirty look (from someone)