The controversy began Friday, when The Exponent ran a "Sex Position of the Week" called "The Prestige," which showed a man having sex with a woman, then switching out with a second man without the woman's knowledge.

More: See Full Cartoon

"If properly executed," read the caption, "the receiving partner will be astonished as if a magic trick has just occurred. Tah-dah!"

The cartoon sparked outrage among some students and bloggers, who accused the paper of advocating rape and demanded an apology from the paper.

"The Exponent is creating an unsafe environment for its female students, as well as depicting females as sexual objects, whose victimization is viewed as a source of entertainment," read a posting on one of several websites, blogs and petitions on the topic.

Exponent Editor In Chief Zoe Hayes, citing a flood of angry e-mails and phone calls, issued an apology on Monday, calling the printing of the cartoon a mistake.

"If someone engages in any sexual act with anyone without his or her explicit consent, it's rape. The comic can easily be interpreted that way," she wrote. "I am particularly angry with myself for missing what is, in retrospect, the simplest and most obvious explanation for the graphic -- that the woman in it is put a position to have nonconsensual sex with the second man."

The Exponent is not affiliated with or funded by the university. School officials said they hope the mistake will serve as a learning experience.

"While respecting free speech, we urge you to respect Purdue University's values and commitment to create an inclusive environment that promotes tolerance and respect of every individual," five top administrators wrote in a letter to the editor. "We encourage you to be more thoughtful and reflective in your editorial review by balancing your freedom of speech with your responsibility to the Purdue community."

Editor's Note: After the initial posting of this article, one of the student-run protest pages linked in the story was redirected to a pornographic site. We have since removed the link and apologize to any readers who may have clicked on the page.