(Image Credit: Tim Roske/Pool/AP Photo)

There was one question Sen. Kirsten Gillibrand and Republican challenger Wendy Long hadn't prepared for during their Wednesday night debate in New York.

"Have you read 'Fifty Shades of Grey'?"

Both women hastily answered "no" when the question was posed during the lightning round of their only debate of the election and the room erupted in chuckles and some applause at Skidmore College in Saratoga Springs.

Long said she went along with the joke but was unamused.

"Frankly, I thought it was just completely bizarre," Long told ABC News. "I was trying to be a good sport and everyone was laughing. But I thought it was completely bizarre and sort of sexist."

As for Democrat Gillibrand, spokesman Glen Caplin said, "The only thing she found offensive last night was her opponent's views that women shouldn't have the freedom to make medical choices for themselves."

The erotic novel, which is part of a series by British author E.L. James, has taken literary culture by storm, selling 50 million copies worldwide and landing on the bedside table of millions of women in the process.

The debate between Gillibrand and Long was moderated by "Capitol Tonight" host Liz Benjamin and NY1 host Errol Lewis. Benjamin posed the question to the candidates during the debate's "lightning round" segment in which the candidates were asked a series of yes-or-no questions.

Benjamin said the lightning round and the "Fifty Shades" question were intended to lighten up an otherwise "tense" debate and to give the candidates a break.

"That book is a cultural phenomenon, got a lot of attention, a lot of eyeballs. So it seemed a pretty apropos question related to current events," Benjamin told ABC News after the debate. "Also, with all the attention on women this cycle, and two women candidates and a woman moderator, it worked."

On "The View" in May, even President Obama was asked to name the "controversial sex book that's on millions of women's bedside tables."

"I don't know that," Obama said. "I'll ask Michelle when I get home. … I'll ask Michelle when I get home what's going on."

Still, Long says she thought the question distracted from an otherwise serious debate, and doubts that a question like that would come up in a debate if the candidates were men.

"There's no way that question would have been asked if it was a man and a woman debating," she said.