Home / Twisty / Doc I Keep Hearing Strange Voices In My Underpants! Birthday Card Doc I Keep Hearing Strange Voices In My Underpants! Birthday Card£3.49 Card Size: 5” x 7”. Blank Inside. Envelope Included. Funny Birthday Card. 5 in stock Doc I Keep Hearing Strange Voices In My Underpants! Birthday Card quantity Add to basket Related products Fully Qualified Grumpy Old Git Birthday Card £3.49 Add to basket For My Old Man Swear At It and Whack It With A Hammer Fathers Day Card £3.49 Add to basket Weight Machines Not Time Machines Birthday Card £3.49 Add to basket Alexa Tell Me Something To Cheer Me Up Birthday Card £3.49 Add to basket