Summer Bikini Beach Buttock

Some articles of clothing are designed to expose the buttocks. Such clothing is not generally worn in public situations; however, it is sometimes considered appropriate to wear such clothing at swimming facilities or at the beach.
Emphasis on one part or another of the body tends to shift with generations. The 1880s were well-known for the fashion trend among women called the bustle, which made even the smallest buttocks appear huge. The popularity of this fashion is shown in the famous Georges Seurat painting A Sunday Afternoon on the Island of La Grande Jatte in the two women to the far left and right. Like long underwear with the ubiquitous 'butt flap' (used to allow baring only the bottom with a simple gesture, as for hygiene), this clothing style was acknowledged in popular media such as cartoons and comics for generations afterward.
More recently, the cleavage of the buttocks could be exposed by some women as fashion dictated trousers be worn lower. (known as a "coin slot", or "vertical smile").
An example of another attitude in an otherwise hardly exhibitionist culture is the Japanese fundoshi.