When you cut your balls shaving before an event and turn up hours later only to realise you never stopped the blood flow and spend the evening with a stiff upper lip whilst your white chinos are forever ruined.
When the male partner dips his nose into a tub of guacamole and then proceeds to rub and poke his nose into the female's rim. The action of rubbing and poking is akin to that of anal fisting-albeit with a nose.