mismate

Phyllie, don't mismate; those that do regret it.

From Tobogganing on Parnassus by Franklin P. (Franklin Pierce) Adams

Of the 1975 comedy-drama "Lucky Lady," for example, he wrote that it was a "cynical, vulgar, contrived, mismated, violent, uneven and uninteresting disaster."

From Los Angeles Times ● Nov. 17, 2014

One listener summed it up: "It didn't take Bernstein to show that they were mismated."

From Time Magazine Archive

Unaware or uninterested that the two are mismated, the matchmakers give their efforts much more sense of ravishment than of matrimony.

From Time Magazine Archive

Sometimes she gets kidded by Announcer Dick Willard and Husband Bill Sauter, a quiet, wisecracking ex-actor who contributes a felicitous conjugal note that draws plaintive queries from mismated listeners.

From Time Magazine Archive

How near had he been to them in the black night while they talked of his wife's mismated beauty?

From The Brimming Cup by Dorothy Canfield Fisher

The similar drug diethylstilbestrol, which Yale researchers are finding equally effective, has been used by veterinarians for years to treat mismating in animals.

From Time Magazine Archive

It was simply a case of mismating, and no good would result from the union.

From Melomaniacs by James Huneker

M. Arouet pater did not marry until his mind was mature, so that he might avoid the danger of a mismating.

From Little Journeys to the Homes of the Great Philosophers, Volume 8 by Elbert Hubbard

In order to explain what perfect marriage is, Swedenborg works by the process of elimination and reveals every possible condition of mismating.

From Little Journeys to the Homes of the Great Philosophers, Volume 8 by Elbert Hubbard

However, they said very little about this mismating to any of their acquaintances, though sometimes Steve would look at James’s wife and sigh, and James would look at Steve’s wife and do the same. 

From Life's Little Ironies by Thomas Hardy