A karass of only two people, who are so bound
together that even their children cannot invade their union. From Kurt Vonnegut's "
Cat's Cradle." (A karass is a group of people bound
together, often without externally discernable ties.)
From "
Cat's Cradle":
“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.”