The man is holding a bow in his right hand, and a string instrument called lira da braccio in his left. The woman sprinkles the instrument with milk from one of her breasts. In the background, we spot a castle-like construction and a shepherd with his flock; he seems to write or draw something on the ground with his staff.
Jan Sanders van Hemessen (c.1500 - c.1566) was a Flemish Northern Renaissance painter who was part of the mannerist movement. He was born in Hemessen in the Netherlands but settled in Antwerp in 1524 after studying in Italy. Hemessen specialised in scenes of human character flaws such as vanity and greed. His pictures are often religious, while his style helped found the Flemish traditions of genre painting.