Most likely the artists of the past were bored with glorifying the usual serene motherhood by picturing enlightened Madonnas who breastfeed Jesus. In the museums we can find lots of paintings that look like a parody of this plot: a woman is breastfeeding a bearded, ugly old man. This was pictured by Rubens, Caravaggio, Greuze and many others.

However this is by no means a parody but a classic plot known since Ancient times.

Roman Charity by Jan Janssens. 1620-1625.

This topic is called in Latin Caritas Romana i.e. Roman charity.

The fable refers to the first century of the common era, app. 30-31 year after the birth of Christ.

It was published by Valerius Maximus, a famous writer by that time.

Roman charity by Rembrandt Peel. 1811.

Cimon has been already old, when he was incarcerated and sentenced to death by starvation.

A good type of punishment indeed – it is inexpensive, clean and handy. The dead body is then easy to take away.

What happened next? You must already guessed from the pictures.

Roman charity by Georg Pents. 1538.

Cimon’s daughter Pero has recently delivered and came to visit her father.
She saw him dying from starvation and gave him her breast milk.
(Because of the pity for the father according to the official version, but in fact Pero had forgotten the electric breast pump at home and the breast was about to burst. Here she found the way out).

Roman charity by Perin del Vaga. 1530.

But they were not alone. The bored jailers observed with interest this physiological process.
They had nothing else better to do. TV was prohibited in the guardroom.
And here they saw even a nude scene!

Roman charity by Rubens. 1630.

Breastfeeding in public is incredibly shocking to people (as we know from Internet holy wars). And this is the case when they feed the baby.
Now imagine how the fragile tender souls of the jailers were shooken when they saw a bearded bald old man torturing a naked breast of a beautiful woman.
Shameless! She could cover herself at least with a sling! Not to shock people!

Roman charity by unknown artist. 17th century.

It is not known whether a portion of mother’s milk of the daughter helped the old man in physical survival. But it helped in another way: jailers voyeurs spread rumors about this shocking spectacle at every corner.

Roman Charity by Januarius Zick. 1797

The information reached the officials.
They were shocked.
By selfless and generous deed of the daughter!
(They obviously never suffered from the lack of a possibility to pump the milk).

Portrait of Count von Hartig with his wife playing role of Cimon and Pero by
Barbara Kraft. 1797
(A hardcore stuff. How could anybody ever thought of doing such a portrait?)

Old Cimon was pardoned.
Young Pero began to be praised as an example of filial piety and dedication.

by Gioacino Serangelli. 1810.

Over time, images of this scene even appeared in Roman temples. Frescoes survived to this day (although not in temples).

Mural from Pompeii

The plot acquired a particular love of artists in the 17th century, however there are paintings from other eras.

Roman charity by unknown artist. 17th century.

Well, here you have the normal image of a nursing mother to compare. 
For aftertaste.