Why do many women show off their ass (by wearing tight mini skirts, leggings, tight dresses)?

[jeemm]

Same reason some don't. To look attractive but each of us have different definitions so we actualize it in different ways.

[Jooying]

Because they are confident. They think they have maintained them nice and are proud to showing them.

[TheFlak38]

Because in the attention competition of the 21st century women win with two ways
1. get naked
2. commit a felony

[Gedaria]

Because people like looking at them..

[jakerson181]

Because they can.