( CNN ) -- A Northwestern University psychology professor was in hot water Thursday for an after-class session in which a couple demonstrated the use of a sex toy . University President Morton Schapiro said he was `` troubled and disappointed '' by the February 21 incident and had ordered an investigation . `` Many members of the Northwestern community are disturbed by what took place on our campus , '' Schapiro said in a statement . `` So am I . '' Professor J. Michael Bailey provided his own account of the optional event in his human sexuality course , saying he wants students to learn about sexual diversity and information from `` real people . '' Students who witnessed the incident had been told repeatedly by a guest speaker what was about to happen would be graphic , the professor said in a statement . About 100 students chose to attend following a larger lecture , affiliate WGN said . Bailey invited speaker Ken Melvoin-Berg , co-owner of Weird Chicago Tours , who brought a woman and a man for a discussion on the female orgasm . Melvoin-Berg suggested they demonstrate use of high-powered equipment they brought , said the professor , who agreed to the idea . `` We gave them plenty of warning . We had nobody leave at that point , '' Melvoin-Berg told CNN Chicago affiliate WLS , adding the demonstration was meant to be educational . `` We only got positive feedback , 100 % positive feedback during and after . The students were respectful . They were smart and asked good questions , intelligent questions and seemed engaged in the idea of human sexuality , '' said Melvoin-Berg . But apparently some students at the private school near Chicago left before or during the demonstration of what the professor described in a statement as `` kinky '' sex . `` For me , I 'm glad I did n't see it . It was a little too explicit for me , and if I were in the class , if I would have stayed for the demonstration , I probably would have left . I know a couple of my friends did get up and leave , '' student Diana Lorenzini told CNN affiliate WLS . Brianne Williams , another student , said `` Dr. Michael Bailey is one of our finest professors here , and his class is about opening people 's minds up . '' Schapiro said he wants to determine what is appropriate for the classroom . `` 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 , '' Schapiro said in his statement . `` I simply do not believe this was appropriate , necessary or in keeping with Northwestern University 's academic mission . '' In his statement , Bailey said it was too early to tell whether he had regrets . `` I certainly have no regrets concerning Northwestern students , who have demonstrated that they are open-minded grown-ups rather than fragile children , '' the professor added .
Northwestern University students see sex demonstration in after-class session . Professor says he wants students to learn about sexual diversity . University president orders investigation of incident . Couple gave live demonstration of sex toy .