NKN is an acronym for Nice kid, nice. NKN is gaining popularity as internet slang, however; it stems from common street slang of individuals growing up , namely breakers (break-dancers), in the early 70's in NYC and other U.S. locations which brewed up the lifestyle and genre we now call Hip-Hop.
Someone who is addicted to obtaining money and building wealth. A money addict and fanatic. Breadheads often work more than one full-time job, and some even participate in illicit activities to "obtain the bread".
I don't buy the schmegegge about Morty sleeping with Moira.
His version of the story was pure schmegegge.
The whole schmegegge was made up to get Liz a little bit of attention.