unmentionable

adj

1. Too embarrassing or shocking to be discussed.

noun

1. Something not to be discussed in polite society.

   “I'm a lesbian female, 20 years old and my most outstanding features are my pierced unmentionable and my eyes.”

   “He was taught from childhood that the world does not condone homosexuality and that it is an unmentionable of decent people.”

   “Here, after all, was the circle round which Forster passed the manuscript of his novel Maurice which conveyed so much about being 'an unmentionable of the Oscar Wilde sort'.”