Mack has two definitions:
A mack can be a person who is smooth, slick, the Best of the Best, a Pimp, a Ladies Man, the guy who runs everything a.k.a. the Boss. A mack is a person who is always flirting and hitting on girls. Almost always successful at it too.

-OR-

Mack can be used as a verb, as the act of flirting and hitting on girls.

The Nussy, or the “nose pussy”, if you will, was discovered during the corona virus pandemic of 2020. People that had to be tested for Covid-19 had to have their nose swabbed right where the brain connects, which often led to people rolling back their eyes and gagging.

A nose-swab-fetish developed from this, because we, as humans, ruin everything.

(verb) to flirt with or attempt to seduce

1. To hit on a girl
2. To eat food intensely

To hit on, flirt with, or seduce another by using verbal or sometimes physical means of persuasion.

mack" may derive from french slang where a pimp is known as a "mac" short for maquereau, or mackerel. Commonly, a mack is a pimp