They were lovebirds. They entertained each other endlessly with little gifts: sights worth seeing out the plane window, amusing or instructive bits from things they read, random recollections of times gone by. They were, I think, a flawless example of what Bokonon calls a duprass, which is a karass composed of only two persons.

Cat's Cradle: A Novel (ed. Dial Press, 2009) - ISBN: 9780307567277