Pompoir is one of several terms relating to the strength of vaginal muscles and their ability to embrace and lock on to the penis in order to prolong erection.
‘For men, pompoir, is an exercise in penile passivity, as all that moves is the vaginal muscles. Using the pelvic floor muscles in this way has been seen for centuries as a way of enhancing sexual pleasure for both partners and controlling sexual timing. It is also enjoyed as an intensely pleasurable means of self-stimulation by women, and it is in this particular pose that a famous statue of the Indian goddess Kameshvari is thought to be sitting in the town of Bheraghat.’
– C. Blackledge, The Story of V: A Natural History of Female Sexuality, 2004.