Hieronymus Bosch (Jeroen van Aken, ca 1450-1516), The Garden of Earthly Delights, triptych (ca 1500), central panel detail 12.
(Source: en.wikipedia.org)

The apotheosis of apparent innocent sexuality is interspersed with numerous irritating factors of perverse behaviour, shown for instance, in the scene where a youth thrusts some flowers into the rectum of his companion.