to "pull a parker" means to say something loudly that either removes someone's ruse or let's someone else understand what exactly is going on, usually in a bad way.
Person 1: "man i was so sick, there was no way i could have shown up at school yesterday."
Person 2: "dude, i went to your house yesterday, you were fine. in fact, you went wake boarding
with me after that"
(nearby teacher hears Person 2, starts to walk towards them)
Person 1: "ugh. you just pulled a parker man."