Muffle Bag Boy Share definition Flag Verb/Adjective- For a girl to use their partners hand to masturbate when they are still asleep. Dude my wife used me as her muffle bag boy last night... Muffle Bag Boy by pittsburgh@412 July 26, 2011 0 0 Get merch Get the Muffle Bag Boy mug. Buy Now — $32.95 See more merch