Rejection of and ridicule for an offered good or service by feigning satiation. When "No Thank You" just won't do.
Person A: "Would you like to try some of my new recipe? It's Guacamole Crab Dip."
Person B: "No, I'm good"
Person A (on the phone): "Hey, Jenny. You've been studying too hard. How 'bout I swing by your apartment and give you a back rub?"
Jenny: "No. I'm good"
Person A: Do you want to go down to the Creepy Crawl and see The Wheezing Coughers?
Person B: "No thanks, I'm good."