About the only way to achieve this is by rubbing up against something-- for example, sometimes when a person is sleeping, they have a sexual dream and they wake up and have an orgasm without even realizing how it happened.
Aliens
Duncan Cumming died in 1979.
Donigan Cumming was born in 1947.
The Cumming Attraction Backstage at 'Macbeth' with Alan Cumming - 2013 was released on: USA: 15 March 2013 (internet)
Hanway Robert Cumming died in 1921.
Mansfield Smith-Cumming died on 1923-06-14.
Primrose Cumming died in 2004.
James Cumming died in 1861.
James Cumming was born in 1777.
Charles Cumming was born in 1971.
Wenche Cumming was born in 1944.
Hildelith Cumming was born in 1909.
Hildelith Cumming died in 1991.
Primrose Cumming was born in 1915.
Laurie Cumming died in 1980.
Kenneth Cumming was born in 1916.
Kenneth Cumming died in 1988.
Dorothy Cumming was born in 1895.