An uncommon greeting, only to be spoken by people with ungodly talent. If said by someone unworthy, yellow balloons will burst from the cranium of the one who speaks it, like bubblegum popping from the mouth of the coolest girl ever.
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.