Their Aching Hungers by Sylvia Sharon

'A demon of desire drew three people into one of the strangest relationships of all time'

From the back cover teaser: 'His desire was as strong as any man's --- but the jeering devils lurking in his grotesquely warped past barred him from complete fulfillment. He'd tried a voluptuously uninhibited mistress. Now he had an ardently pagan wife. Then came a stranger. She led him to the pastures of total abandonment --- And then she invited his wife ---'