When one sucks off another, then as male is about to ejaculate, he states his predicament to the partner who promptly places a thin layer of material, i.e undergarments, over the penis. At this point, said sucker places mouth around partners penis. The penis holder then spurts his 'sex wee' through material. Sucker then sucks semen through material causing filtration. Pleasure ensues.
1. " .... Amy totally gave coffee filtration to me last night!"