This is an entry in Spicymancer's Halloween Competition.
I came up with a story to make this happen, but I didn't have time to write it. Maybe next year.
Assuming some of you may need help parsing my attempt at artwork, I tried to depict undecrypted Jack dressed up as Peter Pan and Jack in Black dressed up as Peter Pan's shadow.
...yeah, I need to work on my artwork.
The "skirt" is the untucked hem of the shirt, but in an effort to include recognizable Jackness I made it into a suit coat with the same triangle hem rather than the Pan shirt with similar triangle hems on the short sleeves. The belt does seem to divide it into a skirt, as drawn.
...and they're supposed to be flying. :/