This time my shameful task is to keep folding the skirt shorter
Moreover, the owner put a remote-controlled vibrator in his underwear.

The experimental result is

on lap
20cm = the length of skirt that Xiao Q usually wears
25cm = If you move too much or bend over, your butt will be exposed
30 cm = slightly exposed buttocks, covering private parts to the maximum extent when looking straight up
35 cm = half of the underwear and butt are exposed
40cm = equal to not wearing a skirt!!

This time my shameful task is to keep folding the skirt shorter
Moreover, the owner put a remote-controlled vibrator in his underwear.

The experimental result is

on lap
20cm = the length of skirt that Xiao Q usually wears
25cm = If you move too much or bend over, your butt will be exposed
30 cm = slightly exposed buttocks, covering private parts to the maximum extent when looking straight up
35 cm = half of the underwear and butt are exposed
40cm = equal to not wearing a skirt!!