Okay, I finally tracked down this quote. It's from De Profundis (written 1897, published 1915), and it's a slight modification:

If after I am free a friend of mine gave a feast, and did not invite me to it, I should not mind a bit. I can be perfectly happy by myself. With freedom, flowers, books, and the moon, who could not be perfectly happy? Besides, feasts are not for me any more. I have given too many to care about them. That side of life is over for me, very fortunately, I dare say. But if after I am free a friend of mine had a sorrow and refused to allow me to share it, I should feel it most bitterly. If he shut the doors of the house of mourning against me, I would come back again and again and beg to be admitted, so that I might share in what I was entitled to share in. If he thought me unworthy, unfit to weep with him, I should feel it as the most poignant humiliation, as the most terrible mode in which disgrace could be inflicted on me. But that could not be. I have a right to share in sorrow, and he who can look at the loveliness of the world and share its sorrow, and realise something of the wonder of both, is in immediate contact with divine things, and has got as near to God's secret as any one can get.

This was written during Wilde's stay in prison for "gross indecency" (read: gay sex).