bad

[No Name Available]

Whenever my students (as well as numerous other teenagers with whom I
interact on a regular basis) make a mistake, and it is brought to their
attention, their response is , "My bag!" It appears to be an embarrassed
acknowledgment of the mistake (It is accompanied by an embarrrased grin.)
In fact, I have, on occasion, jokingly responded to them the same way
whenever I goofed.  Of course, my saying it gets a few chuckles.

Only once or twice have I heard, "My bad."  I assumed that this was a
mispronunciation of the above since it occurs in the same situational context
as "My bad!"
                        PAT

P.S.  Maybe it differs geographically (I am in southcentral Alabama, where
final consonants are often not pronounced in many words, especially after
lengthened vowels.)