A "PajamaJam" is a fun, chill session at night in your pajamas. It was started in the Big Brother house during the 13th season. It was made famous by Dominic "PT" Briones, Daniele "Dani" Donato, Kalia "Sleepy" Booker and Lawon "Superpower wanting" Exum. The fun now continues on Twitter by following PT (aka @dominicphillip)
A night without a PajamaJam is like a day without the sun.