The Northwestern University has defended its professor's decision to hold a controversial after-class live sex show on campus as part of his lecture.
According to Chicago Sun-Times, more than 100 students watched the live show - which involved a naked 25-year-old woman, her 45-year-old fiance, and a sex toy - as part of a course called 'Human Sexuality', reports the Courier Mail.
Four members of Chicago's fetish community were invited to speak and answer questions about 'bondage, discipline, sadism and masochism', but were then asked to demonstrate their sexual behaviour, also known as BDSM.
Faith Kroll said she initially thought she would only be answering students' questions about sex before she and partner Jim Marcus, 45, joined the presentation on February 21.
Prof John Michael Bailey said the students' reaction was 'uniformly positive' and he hesitated "briefly" before allowing the sexual act.
"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," he said.
"I certainly have no regrets concerning Northwestern students, who have demonstrated that they are open-minded grown-ups rather than fragile children," he added.
The professor had reportedly warned attendees several times about what was about to happen.
The university has backed Bailey and said students were not obliged to attend the session to be graded.
A spokesman added that no complaint had been filed with the police.
"The university supports the efforts of its faculty to further the advancement of knowledge," said Alan K. Cubbage, the vice president for university relations.