sink through the floor
Suffer extreme embarrassment, as in When she called our name on the list of those who owed dues, I sank through the floor. This hyperbolic term dates from the early 1900s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.