A flogging cane know as the "cat-o-six-tails" belonging to Louise Valtesse de la Bigne, is displayed together with her portrait, rear, painted by Henri Gervex in 1879 during a press preview of the Easy Virtue exhibition at the Van Gogh Museum in Amsterdam, Netherlands, Wednesday, Feb. 17, 2016. The Van Gogh Museum is dedicating a new exhibition to the world's oldest profession, examining the fascination for prostitution among artists like Van Gogh, Edgar Degas and Henri de Toulouse-Lautrec. The exhibit can be viewed from from Feb. 19 till June 19, 2016. (AP Photo/Peter Dejong)

A flogging cane know as the "cat-o-six-tails" belonging to Louise Valtesse de la Bigne, is displayed together with her portrait, rear, painted by Henri Gervex in 1879 during a press preview of the Easy Virtue exhibition at the Van Gogh Museum in Amsterdam, Netherlands, Wednesday, Feb. 17, 2016. The Van Gogh Museum is dedicating a new exhibition to the world's oldest profession, examining the fascination for prostitution among artists like Van Gogh, Edgar Degas and Henri de Toulouse-Lautrec. The exhibit can be viewed from from Feb. 19 till June 19, 2016. (AP Photo/Peter Dejong)