do a number on (someone)

to treat someone very badly or unfairly.

I'm not surprised Caroline doesn't like him. He really did a number on her at work.

• a slap in the face
• a slap on the back
• a slap on the wrist
• as large as life
• asleep at the switch
• asleep at the wheel
• a slice of life
• a slice of the action
• a slice of the cake
• as like as not
• as likely as not
• a slime ball
• a slip of the tongue
• a slippery slope
• as long as
• a small fortune
• a smart alec
• a smart aleck
• a smart-arse
• a smart bomb
• a smart cookie
• a smart mouth
• a smarty pants
• a smoking gun
• as much as