Updated

Northwestern University is defending a professor who allowed a guest lecturer to demonstrate the use of a sex toy after a class on human sexuality.

The university concedes the demonstration was sexually explicit but says it was all in the pursuit of knowledge.

About 100 students from the class taught by psychology professor John Michael Bailey watched the demonstration, presented by a guest lecturer, after the class last month. Attendance was optional.

The lecturer had given a talk on fetishes and conducted the demonstration with the help of a woman and her fiancé. Bailey warned students the demonstration would be explicit.

Authorities in Evanston say Northwestern police are responsible for determining if any local ordinances were violated by the demonstration. Officials at Northwestern say no one has filed any complaints.