Updated 03/03/11 – 5:10 p.m.

EVANSTON, Ill. (CBS) — The president of Northwestern University says he is “troubled and disappointed” by a live sex demonstration held after a class in a human sexuality course and said it would be “investigated.”

“Although the incident took place in an after-class session that students were not required to attend and students were advised in advance, several times, of the explicit nature of the activity, I feel it represented extremely poor judgment on the part of our faculty member,” Northwestern president Morton Schapiro said in a statement. “I simply do not believe this was appropriate, necessary or in keeping with Northwestern University’s academic mission.”

LISTEN: Newsradio 780’s Steve Miller Reports

Schapiro’s statement came less than a day after university spokesman Alan Cubbage released a separate statement defending Bailey’s decision.

“Northwestern University faculty members engage in teaching and research on a wide variety of topics, some of them controversial and at the leading edge of their respective disciplines,” Cubbage said in an e-mail on Tuesday. “The University supports the efforts of its faculty to further the advancement of knowledge.”

The demonstration was part of an optional after-class presentation in professor John Michael Bailey’s human sexuality class. The students who attended ended up seeing a woman lying onstage, in person, being penetrated by a motorized sex toy.

Schapiro said even though academic courses will often explore controversial topics, the sex demonstration crossed the line.

“I have directed that we investigate fully the specifics of this incident, and also clarify what constitutes appropriate pedagogy, both in this instance and in the future,” he said in the statement. “Many members of the Northwestern community are disturbed by what took place on our campus. So am I.”

As CBS 2’s Mike Puccinelli reports, it was the cover story in the student paper on Wednesday and has been the talk of campus the past two days.

“Doctor Bailey’s after-class presentations are always interesting and really different,” Northwestern sophomore Caitlin Mead said.

Mead is a student in Bailey’s human sexuality class and she was one of more than 100 students who chose to watch as a nude woman took part in a live sex demonstration.

“He works to show sexual diversity and, though the presentation was pretty explicit, he gave us fair warning,” Mead said. “It was an optional event and everyone there knew what was going to happen.”

She also said she believes Bailey was trying to entertain his students.

Whatever he was trying to do, Bailey wasn’t saying on Thursday. He wasn’t available for comment, either at his home or his office.

Asked what she learned from the sex demonstration, Mead said, “I wouldn’t say I learned anything new.”

Northwestern staffer Hillary Bean is one of many who said they were disturbed by what she’s heard about the live sex demonstration.

Bean, an employee at the university’s financial administration, said Bailey has been stretching the bounds of decency for a long time.

“I think he’s got a long record of being difficult and should be investigated,” she said. “Professor Bailey has been getting away with a lot of unusual things for a long time.”

Bean wouldn’t say if she thinks Bailey should be fired, but Mead said she doesn’t think the demonstration should cost Bailey his job.

“I think Professor Bailey is one of the best, if not the best professor that I’ve had at Northwestern,” Mead said. “I think he is just looking to tell us the truth.”

But Bean said Bailey’s poor decision turned the ivory tower of academia into something more like a downtown red light district for a time last week.

“Live sex demonstrations probably shouldn’t be in the classroom of a top Big Ten university of the caliber we have,” she said. “Granted it was an optional after-class (event) but nonetheless, I don’t believe it’s terribly appropriate.”

Guest speaker Ken Melvoin-Berg had come for a discussion on the woman and her fiancé with him to the Feb. 21 presentation on “Networking for Kinky People.”

Along with a “variety” of other items, they brought a “sex saw,” Melvoin-Berg told CBS 2’s Kristyn Hartman. The device in question is described by the Daily Northwestern as “essentially a motorized phallus.”

Melvoin-Berg said the students who stayed after class were informed of the graphic content over a dozen times, and received more warnings before a man used the sex saw on his fiancée in the live demonstration.

“(The woman) got on stage and took her pants and her panties off. She lay down on the stage and put a towel underneath her,” Melvoin-Berg said. “Then (the man) plugged saw in. He brought her to orgasm right there on stage. That was the end of it, other than the fact that we had positive comments from everybody in the class.”

In a written statement, Bailey echoed the remark, calling reaction to the demonstration “uniformly positive.” He said while he briefly had doubts about the live sex demonstration because he knew many students would find it “inappropriate,” he decided to approve it.

“My decision to say ‘yes’ reflected my inability to come up with a legitimate reason why students should not be able to watch such a demonstration. After all, those still there had stayed for an optional demonstration/lecture about kinky sex, and were told explicitly what they were about to see,” he said

Read Bailey’s Statement

At least one Northwestern parent has called for his dismissal.