>>101399908Not seriously, no.
While the boob window has been dubbed a joke, key holes are commonly used in fashion and in comic designs usually serve a similar purpose to logos or color breaking design elements.
Butt Windows are in a location where that's just not as useful. However I'm bias since I've never seen anyone try to use it other than in instances like yours.
Only way I can see it being seriously done is trying to take an open back design making it dive lower to probably the asscrack then closing it up just above the upper small of the back.
