Fresco: Cupid holding a rhombus

Venus sits on a chair or throne in the foreground dressed in a loosely draped garment. Mars stands behind the chair wearing a helmet with a large crest; some sort of cloak or cloth is draped over his left shoulder. He reaches around to grope Venus with his left hand. Venus reaches up with her left hand grasping his elbow. Cupid, shown as a winged cherub, hovers in the background holding a rhombus.

Cupid holding a rhombus, with Mars and Venus (1st c. AD.). Fresco from Pompeii, casa di amore punito. 

Online Resources
Image Source: Theoi
Associated Passages
Ovid, Amores 1.8