Post-Ironic Sinceritism

The act of phenomena of when you use a phrase or word in a sincere or unironic manner, that originally was only used or meant in an unironic manner.

"What up, Fam"
"Bro, did you just say 'Fam' unironically? You used to make fun of people who say that."
"Oh shit... I guess I did."
"That is called Post-Ironic Sinceritism"