A passive-aggressive phrase used to show someone that you don't care, though you're actually hurt and/or angry on the inside. Often used with "be that way."
Amy: "Bob, I can't go see a movie with you, I'm busy."
Bob: "Well fine then."
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.
We have a Zoom meeting in a few minutes and I’ll probably go pajama casual.