Irritated sphincter caused by over-active bowels due to consuming large amounts of draft beer Friday and Saturday. Usually stems from not abusing alcohol during the week, then compensating for the hiatus by binging through the weekend. Sometimes involves a hemorrhoid or two.
#1. My friend could not go mountain biking with us last week because of his Sunday Ass.
#2. Why does that bar have to have Miller Lite specials over the weekend? I end up with Sunday Ass every time I try to save a little coin.