The professor of a college sex education class invites his students over to his house for a study session and live demonstrations of technique.
United States of America
58 minutes
1973

1971
6.2

2016
0.0

2019
6.1

1991
6.1

1983
7.5

2008
6.9

2007
5.5

2010
0.0

2020
4.3

1956
4.8

1972
4.2

1971
5.5

1973
5.0

1974
4.3

1974
4.0

1975
4.2

1976
5.3

1977
4.8

1978
4.4

2008
4.5