Manu Smriti 2.215

A man must not see
A woman,
Her sister,
Her daughter,
Or even her mother,
In a place of solitude.

For his desires for them
Might get so aroused
As to betray him,
Even he is a Brahman.

~Manu Smriti 2.215

PS: Original in Sanskrit. Rendering from a literal English translation.