If and only if your wife has a good sense of humor try this one time.
Lift the lid on the old porcelain god.
Loosely drape Saran wrap over the bowl. (Be sure to get good coverage.)
Place the lid back down and wait for the fun to start.
Oh by the way don't forget about your little booty trap you have placed.
I know this is sick but it was funny as he** when it happened to my wife.