that's one on you

that's one on you

That is a mistake or joke that makes you look rather foolish. The guy down the road said it would clean your engine and charged you double for it? But that's just normal gasoline. I guess that's one on you. I can't believe you fell for that—that's one on you!
See also: on, one
Farlex Dictionary of Idioms.
See also:
  • a fool and his money are soon parted
  • fool and his money are soon parted
  • fool and his money are soon parted, a
  • parted
  • cost (someone) dearly
  • dearly
  • doofus
  • (there's) no fool like an old fool
  • be (not) (one's) bag
  • experience is the teacher of fools