that's one on me

Idioms  

1. That's a joke at my expense, as in And after all that discussion they didn't show up—that's one on me. This phrase must be distinguished from that's a new one on me, which means “this is the first time I've heard of or seen that” (as in A checkerboard rug—that's a new one on me). Both idioms can be used with other personal pronouns (for example, that's one on you) and date from the early 1900s.

---

Example Sentences

“Now, that’s one on me, Scotty—” “Oh, it was a bluff, and Fisty didn’t have the nerve to call it.”

From Lost Farm Camp by Knibbs, Harry Herbert

"I been a sailin' the seas for forty years—but that's one on me!"

From The Victim A romance of the Real Jefferson Davis by Dixon, Thomas

I guess I'll own up that's one on me.

From Dick Randall The Young Athlete by Clark, Ellery H.

"All right, that's one on me," said Tom.

From The Rover Boys on the Plains The Mystery of Red Rock Ranch by Stratemeyer, Edward