The love that dare not speak its name is a phrase from the poem “Two Loves” by Lord Alfred Douglas, published in 1894. It was mentioned at Oscar Wilde’s gross indecency trial, and it is classically interpreted as a euphemism for homosexuality.
http://en.wikipedia.org/wiki/The_love_that_dare_not_speak_its_name
During his trial Oscar Wilde said...
‘It is impossible to get a conviction for sodomy in England - half of the English don’t think it is physically possible - and the other half are doing it.’
He was convicted.