hit (someone) where it hurts (most)

to do something which will upset someone as much as possible.

She hit him where it hurt most - in his bank account.

If you want to hit her where it really hurts, tell her she's putting on weight again.

• lay into something
• lay it on the line
• lay it on thick
• lay low
• lay off
• lay off something
• lay of the land
• lay on
• lay on someone
• lay on the line
• lay open
• lay open to
• lay out
• lay out something
• lay over
• lay someone low
• lay someone off
• lay someone open to something
• lay someone to rest
• lay someone up
• lay something at door
• lay something at someone's door
• lay something on
• lay something on someone
• lay something on the line