Let down

The boy ordered a sonic screwdriver with his Christmas money. For three days, he wagged his wrists in excitement and stalked the postal carrier. Today, he skidded in out of the downpour, clutching a box to his chest. Since he had ordered it with his grandmother, her name was on the label, and I suggested he wait until she came home to open it, just in case. He worked on his homework, feet drumming and eyes drawn to the little amazon package. My mother came roaring up through the rain on the motorcycle with a garbage bag tied around her with yellow danger tape. As she unwrapped herself, Gavin bobbed eagerly on the chair - "It came! It came! Can I mess with it for a bit and then finish my homework? Pleeeeease?" She took the box and said, "Well, let's see." He hovered, vibrating with excitement, as she ripped the tape off, threw the box open, and revealed... a package of  ladies' underwear. "Sure, you can mess with those all you want!" I said generously. 

"MY SONIC SCREWDRIVER IS GRANNY PANTIES."

Well, neither can open a wood door. Close enough.