Post-Ironic Sincerity

The act of using 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 some Post-Ironic Sincerity"