shotgun wedding

noun3

1. •
   (slang) A wedding in which the bride is already pregnant.
2. •
   (slang) A wedding made in haste or under duress.
3. •
   (slang) Any similarly reputedly forced partnership, between people, organizations, components, or concepts.

   • But all this fails when we try to have a shotgun wedding between the two great theories of nature, relativity and quantum theory. — 2021