Fish fingers result in the aftermath of penetrating a vagina with ones phalanges. The vaginal discharge created due to the resulting orgasm is what creates the pungent odour similar to that of fish fingers (the food) or sushi (sashimi or any other raw fish). The strength of the smell can be rated on a scale of one to ten depending on the strength of the orgasm and how much natural lubricant is produced by the females genitals. In laymens terms if your fingers don't stink your shit. And if this is the case and the woman you were with moaned, you just witnessed a fake orgasm.