WWMMOWS

(well,) wash my mouth out with soap

A sarcastic exclamation of mock regret over a statement someone else found or might find offensive, objectionable, or tasteless. A: "You could at least watch your language around my kids!" B: "Oh, I'm sorry, is it too harsh for their sensitive little ears? Well, wash my mouth out with soap." Are you upset? Am I being too mean? I guess I ought to wash my mouth out with soap, huh?
See also: mouth, out, soap, wash
Farlex Dictionary of Idioms.

Well, wash my mouth out with soap

and WWMMOWS
sent. & comp. abb. a request indicating pretend remorse for saying something profane or objectionable. So you don’t like my advanced vocabulary. WWMMOWS.
See also: mouth, out, soap, wash

WWMMOWS

verb
See Well, wash my mouth out with soap
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • (well,) wash my mouth out with soap
  • soap
  • Well, wash my mouth out with soap
  • excuse you
  • hoo-rah
  • manual