cast/draw/throw a veil over something
draw a veil over
Conceal or avoid discussing something; keep from public knowledge. For example, Louise drew a veil over the accounting errors. [c. 1700]
draw a veil over something
If you draw a veil over something, you deliberately do not talk about it because you want to keep it private or because it is embarrassing. It would be kinder, perhaps, to draw a veil over the party's career from 1906 to the outbreak of the War. Most of us have something in our past career over which we choose to draw a veil. Note: A veil is a piece of cloth used by a woman to cover her face.