Hieronymus Bosch (Jeroen van Aken, ca 1450-1516), The Garden of Earthly Delights, triptych (ca 1500), central panel detail 10.
(Source: en.wikipedia.org)

The apotheosis of apparent innocent sexuality is interspersed with numerous irritating factors of perverse behaviour. In this sense are pictured the couple enclosed in a bubble, the pair nearby concealed in a mussel shell and the man plunged head first into the water and shielding his private parts with his hands.