To have recreational intercourse with a person of the opposite sex, then forget it ever happened and have no emotional attachments afterward. Only works if the female does not get pregnant.
Hey sexy, wana fuck? What? You got a boyfriend? It's alright, just fuck and forget.
When you have a Mexican party to go to and you forgot the guacamole; in metaphor - You forgot how important it was and you're probably about to get chewed out for that shit
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.