shotgun wedding

or shotgun marriage

noun

1. a wedding occasioned or precipitated by pregnancy.
2. Informal. a compromise, merger, accord, etc., occasioned by necessity:

   The coalition government was obviously a shotgun wedding.

shotgun wedding

noun

1. informal.
   a wedding into which one or both partners are coerced, usually because the woman is pregnant

Word History and Origins

Origin of shotgun wedding¹

An Americanism dating back to 1925–30

Idioms and Phrases

An agreement or compromise made through necessity, as in Since neither side won a majority, the coalition government was obviously a shotgun wedding . This expression alludes to a marriage precipitated by a woman's pregnancy, causing her father to point a literal or figurative gun at the responsible man's head. Its figurative use dates from the mid-1900s.

Example Sentences

But there are some clues that this may be a shotgun wedding.

From The Daily Beast

And about when do you plan that this defense marriage—this shotgun wedding—is to take place?

From Project Gutenberg