Depends. IF you drink the Guinness BEFORE you make the bed you're surely not going to spill the Guinness on the sheets. If you drink the Guinness in bed.....well there is the possibility that you could spill it IN BED and that would be a total waste (except that I have a waterproof mattress pad which would still allow me to slurp my Guinness through the sheets). Hmmm..... cotton filtered Guinness.