What does gay male anal bleaching mean?

The actual 'bleaching' of the skin around the anus, for those with light colored skin.

About

Purely for cosmetic purposes, a cream containing an active ingredient, hydroquinone, is used to 'bleach' the skin around the anus.

The concentration is about 20%.

There is no practical purpose for such 'bleaching'.

Noteworthy: Banned in many countries, the active ingredient is considered to be carcinogen.