She and Mr. van der Luyden were so exactly alike that Archer often wondered how, after forty years of the closest conjugality, two such merged identities ever separated themselves enough for anything as controversial as a talking-over.
There are no more uses of "controversial" in the book.
Show samples from other sources
It might be a good idea, as long as your grade comes up and you don’t get controversial.
Laurie Halse Anderson -- The Impossible Knife of Memory
My father also loved to write poetry, sometimes about love, but often on controversial themes such as honor killings and women’s rights.