When a incredibly annoying person sneezes very loudly and sounds extremely fake, usually to attract attention to him/herself in the hopes of a "bless you" from their peers but doesn't because everyone hates them.
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.