An onomatopoeia relating to the sound of rythmicsexual thunderclaps due to the violent collisions between a man and woman, or the quick faint rythmic souncs of male masturbatinon.
Rick stoodstunned by the bathroom door when he heared a faint fapfapfap instead of running water.
By Dinny
Fapfapfap
Originally the onomatopoetic rendition of male masturbation in Japanese manga (erotic comics), using the Roman letters. "Fapfapfap" has come to represent male masturbation in general, and by extension the slapping sounds of any anal intercourse, and male/female penile-vaginal intercourse as well.